TRB Special Report 300 - Achieving Traffic Safety Goals in the United States: Lessons from Other Nations (2010)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

4 Case Studies of Safety Interventions C hapter 3 described how successful traffic safety programs in other countries function effectively at three levels: the technical implementation of specific countermeasures, agency-level management and planning of the safety program, and maintenance of political and public support. Political leadership has been essential to successful safety initiatives in other countries, at the U.S. federal level, and in the U.S. states. Sustained, high-level political support provides resources, accountability, and buffering from opponents of rigorous interventions. Communication between political leaders and the professional and research communities also has been vital in ensuring that political initiatives lead to effective safety interventions. The experience of safety programs in the United States and abroad also shows that leadership and competence of senior public-sector executives are critical. Managers must define safety program objectives and strategies, budget and allocate resources, coordinate programs across agencies, evaluate the effectiveness of interventions and progress toward program objectives, and communicate expert advice to elected officials. To learn about the sources of leadership and management commitment, the committee examined case studies of the development and implementation of particular countermeasures in the United States. The cases focus on single categories of safety problems and countermeasures for the sake of simplicity, but it is recognized that traffic safety strategy must be comprehensive, integrating driver behavior regulation, road engineering, vehicle safety, and medical services. The objective of the case studies was to examine whether progress is being made in the United States against the selected categories of traffic hazards, to identify the sources of progress and obstacles to progress with regard to those hazards, and to compare the U.S. experience with experiences in other countries. If U.S. progress has been slower than abroad in any of the cases, the difference may be that other countries’ intervention techniques, or their management of interventions, are more effective than methods used in the United States. Alternatively, differences may reflect changes in risk factors such as travel patterns. The case studies do not constitute a comprehensive catalog or review of effectiveness of countermeasures. As Chapter 1 explained, the committee did not survey all categories of safety practice. Among the categories not examined in the cases are countermeasures aimed at distracted driving, aggressive driving, and drug-impaired driving; truck safety programs; driver training; vehicle safety rating; vehicle design improvements; graduated drivers’ licensing; and emergency medical response. The omitted categories include some areas of U.S. success and leadership (e.g., graduated licensing) as well as some (e.g., vehicle improvements) that probably account for important shares of recent traffic safety improvement in the benchmark countries. Some of the omitted categories can make important contributions in the future. For example, safety agencies worldwide have recognized the great potential of in-vehicle information technology applications for reducing crash risk (Farmer 2008). Technologies being tested can effectively and instantaneously warn drivers of external collision risks and of their own high-risk driving behavior (e.g., unsafe speed) and can intervene in vehicle control in high-risk situations. The five intervention cases selected were alcohol-impaired driving prevention, speed control, seat belt laws, motorcycle helmet laws, and practices with regard to roadway hazard 93 

94 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations elimination and safe road design. These five kinds of safety interventions present contrasting management, compliance, and legislative challenges. Seat belt laws and helmet laws are primarily state legislative issues; the laws are effective and relatively easy to enforce once enacted. Impaired driving prevention and speed control are ongoing management responsibilities of state and local law enforcement and highway agencies; the legislature is responsible for laws concerning limits, penalties, and enforcement techniques and for providing agency resources. Highway network screening (identification of high-hazard locations) has been largely a federally motivated activity, with federal grants partially paying for state capital improvements to correct high-hazard locations and for state data systems to identify locations; the legislature’s responsibility has been to provide resources for the program. In general, helmet laws are highly visible issues politically, impaired driving and speed control receive legislative attention when regulations are revised or automated enforcement is proposed, and highway network screening receives attention only when a particular hazard attracts local interest. For each of the case study topics, the sections below describe the following: • The value of the safety intervention: the magnitude of the safety problem addressed and the potential effectiveness of the intervention in reducing risk. It is important to know whether safety management and political leadership are steering safety practices in a productive direction. • Trends in crashes and fatalities that are related to the risks addressed and trends in government attention and resources devoted to the problem. • Benchmark nation comparisons: comparison of U.S. trends and practices with those of other countries with successful safety programs. • Illustrative histories of particular U.S. state or federal regulations and safety initiatives. Ideally, the histories would reveal the nature of the political forces that motivated actions of legislatures on safety laws, safety budgets, and oversight of safety programs; the relationship between public opinion and political leadership; and the importance of management leadership and skills within government agencies as sources of improved safety practices. • Conclusions on how political and public support and management commitment have been obtained. Although management practices and allocation of resources differ among the benchmark countries, a suite of countermeasures recognized as accepted practice and addressing the full range of risks is in general use in all the high-income countries. Application methods have been codified and scientific evaluations of many have been carried out (e.g., Hedlund et al. 2009; Dinh-Zarr et al. 2001; Shults et al. 2001; TRB 2003–2009). ALCOHOL-IMPAIRED DRIVING PREVENTION The sections below describe trends in measures of alcohol-impaired driving in the United States and in selected benchmark countries, interventions that are applied in the benchmark countries and in the United States to curtail alcohol-impaired driving, and the U.S. federal government role in impaired-driving prevention. The final section contains concluding observations. 

Case Studies of Safety Interventions 95 Trends in Alcohol-Related Fatalities The best evidence of the success of national campaigns against alcohol-impaired driving would be a decline in the percentage of drivers on the road with a blood alcohol content (BAC) level above some threshold. However, data for a sample of all drivers are almost never available. Instead, data on BAC levels of persons involved in crashes usually are used to indicate the magnitude of the drunk driving problem and the success of interventions. For example, the National Highway Traffic Safety Administration (NHTSA) tabulates numbers of alcohol-related fatal crashes, defined as fatal crashes in which at least one driver or one involved pedestrian had a BAC exceeding 0.01 percent. A decline in the annual number of alcohol-related crashes is weak evidence of success of impaired-driving prevention efforts if the total of all crashes is declining at a similar rate. When such a trend is observed, it is possible that other factors (e.g., more general highway safety measures, speed reductions caused by increased congestion) are reducing the frequency of all kinds of crashes and that anti–drunk driving activities are having little effect. However, a faster rate of decline in the number of alcohol-related crashes than in all crashes is better evidence of the success of anti–drunk driving interventions. (On “related factors” in fatal crash statistics, see Box 4-1.) Another difficulty in measuring the impact of BAC programs is that only about 40 percent of U.S. drivers involved in fatal crashes receive BAC tests. Drivers who receive tests are unlikely to be representative of all drivers in fatal crashes. NHTSA estimates the total frequency of alcohol-related fatal crashes from the reported BAC data (Subramanian 2002), but the reliability of the estimates is difficult to judge. Comparisons among countries are complicated further by differences in definitions of an alcohol-related crash and in methods of data collection. Finally, crash records in the United States and other countries indicate the presence of an impaired driver or pedestrian, but not whether the impairment was a cause of the crash. Some fraction of the alcohol-related fatal crashes would have occurred even if none of the involved persons had been impaired. U.S. Trends NHTSA estimates show progress in reducing the share of traffic fatalities that are alcohol-related from the early 1980s until the mid-1990s. Since that time, progress appears almost to have ceased (Table 4-1). Roadside surveys of alcohol impairment conducted by NHTSA in 1973, 1997, and 2007 and by the Insurance Institute for Highway Safety (IIHS) in 1986 indicate continuous decline in the frequency of impaired driving throughout this period (Table 4-2). In these surveys, a random sample of drivers is stopped and asked to submit to an alcohol test voluntarily. The response rate in the 2007 survey was high, and the analysis included imputation of the impairment rate among nonrespondents on the basis of responses to supplementary survey questions. Eighty-six percent of drivers stopped provided a breath sample; BACs for 87 percent of those who refused could be estimated from a passive alcohol sensor reading (Compton and Berning 2009). 

96 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Box 4-1 “Related Factors” in Fatalities The NHTSA Fatality Analysis Reporting System (FARS) traffic fatality database includes information on circumstances of crashes that are believed to be related to crash risk or to the expected severity of the crash. The numbers of fatalities in 2007 determined by NHTSA to be speeding-related and alcohol-related and the number of deaths of light-vehicle occupants who were not using restraints (seat belts or safety seats) were as follows: Type of Fatality Number Speeding-related fatalities 13,040 Fatalities in crashes in which a driver had BAC ≥ 0.01 percent 15,387 Car or light-truck occupants killed who were not wearing restraints 14,390 More than one of these factors were present in some fatal crashes. Total fatalities in 2007 were 41,259. NHTSA’s bases for these classifications are as follows: Speeding-related: A driver involved in the crash is charged with a speeding-related offense • or a police officer indicates that racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in the crash (NHTSA 2007d). As the section on speed in this chapter describes, the great variation among the states in the fraction of fatal crashes coded as speed-related suggests that this classification is not consistently coded in the FARS data. Restraint use: Use is determined by police reports. Of the 29,000 passenger car and light- • truck occupant deaths in 2007 in FARS, 7 percent are reported as as “restraint use unknown,” 42 percent as “restraint used,” and 49 percent as “restraint not used” (NHTSA 2008a, 40). Alcohol-related: Before 2008, NHTSA’s annual FARS summary (e.g., NHTSA 2007b, 32) • reported “total fatalities in alcohol-related crashes,” defined as the number of deaths in crashes in which a driver or involved nonoccupant (e.g., a pedestrian) had a BAC ≥ 0.01 percent. Starting with the FARS 2007 summary report, the term “alcohol-related crashes” is no longer used, and NHTSA tabulates only crashes in which a driver had BAC ≥ 0.01 percent (NHTSA 2008a, 7, 32). For fatal crashes in which alcohol test results are unknown, NHTSA estimates the distribution of driver BAC levels. (continued) 

Case Studies of Safety Interventions 97 Box 4-1 (continued) The related-factors data may have use in setting priorities for enforcement of driver behavior regulations but must be interpreted with caution. Characterizing the alcohol and speeding data as tabulations of crash causes would be inaccurate, since there is little basis for estimating what fraction of alcohol- or speeding-involved fatalities would not have occurred if these related factors had not been present. Conversely, some crashes not coded as “speed- related” probably would have been avoided or mitigated if the vehicles involved had been traveling at lower speeds. The decline in the fraction of all fatalities determined to be alcohol-related is consistent with the pattern of enforcement effort in this period. Arrests for alcohol-impaired driving increased by 300 percent from 400,000 in 1970 to 1.6 million (1 arrest per 100 licensed drivers) in 1983, the period of rapid reduction in the fraction of crashes that are alcohol-related, and has since declined (Figure 4-1). TABLE 4-1 Trends in Alcohol-Related Crashes and Pedestrian Fatalities, 1982–2008 1982 1995 2005 2008 Fatalities in alcohol-related crashesa Number 24,200 16,000 16,100 13,900 Number as a percentage of all traffic fatalities 55 38 37 37 Percentage of pedestrians killed who had BAC > 0 49 41 39 42 a Before 2008, NHTSA defined an alcohol-related crash as one in which any involved driver or pedestrian had a BAC > 0. NHTSA tabulations no longer use this term. The values shown in the table for fatalities in alcohol-related crashes as a percent of all fatalities is the fraction of all fatalities that occurred in crashes in which any driver had a BAC > 0. SOURCE: NHTSA 2009c, Tables 13, 20. TABLE 4-2 Percentage of All Drivers with BAC ≥ 0.8 g/L 1973 1986 1997 2007 Weekend nighttime drivers 7.5 5.4 4.3 2.2 Drivers younger than legal drinking age 5.5 3.0 1.3 0.9 SOURCE: Compton and Berning 2009, Figures 1 and 5. 

98 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations 150 140 130 120 110 DUI arrests: index 100 2006=100 90 Pct. of fatalities occurring in crashes in which highest 80 BAC was 0 70 60 50 40 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 FIGURE 4-1 Driving-under-the-influence arrests and alcohol-involved fatalities, 1970–2007. (SOURCE: Pastore and Maguire n.d., Tables 4.27.2007, 3.103.2006.) Since 1995, the decline in the percentage of pedestrians killed in traffic accidents who had positive BAC has been nearly as great as the decline in the percentage of all traffic fatalities that are alcohol-related. Because most intervention efforts are aimed at drivers, the similarity of the trends in driver and pedestrian alcohol involvement suggests that factors other than the interventions may be driving the trends. The percentage of traffic fatalities that are alcohol-related is close to the national average in most states, but some states are outliers. In NHTSA estimates for 2005, 45 percent or more of all fatalities were alcohol-related in 11 states and the District of Columbia (Alaska, Delaware, District of Columbia, Hawaii, Montana, North Dakota, Rhode Island, South Carolina, South Dakota, Texas, Washington, and Wisconsin). The highest shares were 55 percent in the District of Columbia and 51 percent in Hawaii. The lowest shares were 13 percent in Utah and 26 percent in Iowa (NHTSA 2007b, Table 114). International Comparisons Most of the benchmark countries track alcohol-related crashes by using measures similar to those of the United States. Trends are summarized below for four countries noted for strong anti– drunk driving controls. In general, experiences in the United States and internationally appear similar: slowing progress over the past decade in reducing the fraction of all crashes that are alcohol-related. In Great Britain the proportion of all fatally injured drivers who had BAC over the 0.08 percent (0.8 g/L) legal limit declined from the early 1970s through the mid-1990s but since has crept upward: 

Case Studies of Safety Interventions 99 1975 1995 2005 Percentage of all fatally injured drivers with BAC > 0.8 g/L 35 21 24 Fatalities in accidents involving illegal alcohol levels 1,500 540 550 In 2006, police administered 602,000 roadside screening breath tests in England and Wales. Authorities speculate that the cause of the recent lack of progress is a reduction in the frequency of tests. However, the number of tests in 2006 was greater than in any year before 1994 and the number of convictions resulting from the tests is unchanged from the 1990s (DfT 2008, 27–31; DfT 2007, 27–31; Sweedler et al. 2004). Since at least 1975, Germany has steadily reduced the proportions of all traffic injury crashes and of all traffic fatalities that are alcohol-related, defined as crashes in which at least one involved person had a BAC exceeding 0.3 g/L (data in all years include East Germany): 1975 1995 2005 Alcohol-related injury accidents Number 52,000 37,000 22,000 As percentage of all injury accidents 14 10 6 Alcohol-related fatalities Number 3,500 1,700 600 As percentage of all fatalities 20 18 11 Gains are still being made, although the trend appears nearly to have flattened after 2000, after a spike in the early 1990s followed by a steep decline in the late 1990s (Schoenebeck 2007; Sweedler et al. 2004). Recent traffic safety trends have been affected by the reunification of East and West Germany. The former Eastern bloc countries experienced rapid growth in automobile travel and have higher injury and fatality rates, but more rapid rates of improvement, than the West. In Australia, the fraction of all fatally injured drivers and motorcycle riders with BAC exceeding the 0.05 percent (0.5 g/L) legal limit fell from 44 percent in 1981 to 30 in 1992, but then fluctuated between 26 and 30 percent through 1998. The fraction of all fatalities that were alcohol-related fell from 43 percent in 1988 to 35 percent in 1992, then fluctuated between 35 and 38 percent from 1992 to 2001. More recent data are not available (IIHS 2005; Haworth and Johnston 2004; Sweedler 2007). In Sweden, the fraction of fatally injured drivers who had BAC exceeding 0.02 percent rose from 19 percent (43 out of 230 drivers killed) in 1998 to 27 percent (50 out of 187) in 2004, then declined to 24 percent (48 out of 200) in 2007 (Swedish Road Administration 2009, 32). In 1992 the legal BAC limit was changed from 0.05 percent to 0.02 percent. Enforcement, including random breath testing on a large scale, was intense for several years after 1992. Enforcement efforts have been reduced somewhat since their peak in the 1990s. Also, per capita alcohol consumption was increasing between 1996 and 2002 (Sweedler et al. 2004; Sweedler 2007). Swedish Road Administration officials interpret the recent increase in the percentage of drivers in fatal crashes who are alcohol-impaired as partly the consequence of the reduction in the total number of fatal crashes, while the frequency of impaired driving has remained constant (Breen et al. 2007, 30). 

100 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Interventions Deaths and injuries caused by alcohol-impaired driving are one manifestation of the complex social and public health problem of alcohol abuse. Consequently, a range of interventions is needed, and strategies combine measures that attack the broader public health problem with more narrowly targeted traffic safety measures. A NHTSA report has categorized the available countermeasures as follows (Hedlund et al. 2007, 1-2–1-4): • Deterrence: action to enact, publicize, and enforce laws against alcohol-impaired driving: — Laws: administrative license revocation at time of BAC test failure, test refusal penalties, stronger sanctions for higher-BAC drivers, laws against open containers, young driver restrictions — Enforcement techniques: sobriety checkpoints, saturation patrols, integrated enforcement (e.g., combined seat belt and alcohol campaigns), preliminary and passive breath test devices — Adjudication: court sanctions (license revocation, fines, jail, community service), elimination of diversion programs and plea bargains that expunge alcohol-related offenses from offenders’ records, special driving-while-intoxicated (DWI) courts, citizen monitoring of court handling of impaired-driving cases — Offender monitoring: monitoring of sentence completion, alcohol interlocks • Prevention: actions to reduce drinking and to prevent drinkers from driving — Responsible beverage service (training of beverage servers) — Alternative transportation provision — Designated drivers — Alcohol screening and brief intervention in general medical practice — Underage drinking and other alcohol sales enforcement • Communications: establishment of positive social norms with regard to drinking and driving Mass-media campaigns — School and youth education programs — • Treatment to reduce alcohol dependency among drivers, including court assignment to treatment • General traffic safety measures that protect impaired drivers as well as others, for example, enforcement of seat belt laws Interventions in the Benchmark Countries The interventions used in the benchmark countries that are believed to have the greatest effectiveness are high-frequency roadside alcohol testing, low BAC limits, intensive follow-up on offenders through the judicial system, and the coupling of social marketing techniques with enforcement. Ignition interlocks that prevent an alcohol-impaired person from operating a motor vehicle are coming into use in several countries. Laws, enforcement methods, and intensity of enforcement against impaired driving in France, Australia, Sweden, and the United Kingdom are summarized in Chapter 3. Random alcohol test checkpoints (that is, enforcement in which all drivers stopped at a roadside 

Case Studies of Safety Interventions 101 checkpoint are tested, not only those for whom the enforcement officer has grounds to suspect impairment) are used in France, Australia, and Sweden and in most European countries except the United Kingdom, but they are illegal in the United States as a violation of the Fourth Amendment’s protection against unreasonable searches. As described in Chapter 3, rates of alcohol testing in many countries are high enough that a driver can expect to be tested at least once every few years [for example, 280 tests per 1,000 drivers annually in France (Table 3-1)] and appear much higher than U.S. test rates, although few U.S. data on enforcement effort are available. In nearly all of Europe except the United Kingdom and Ireland, and in Australia, the per se BAC limit is 0.05 percent or lower. The limit is 0.08 in the United States, Canada, and the United Kingdom. U.S. Intervention Priorities For transportation officials responsible for proposing or carrying out an impaired-driving prevention program, selecting from among the possible countermeasures to design a strategy depends on a balancing of effectiveness, cost, and political feasibility. Research has evaluated the effectiveness of many of the countermeasures listed above (Hedlund et al. 2009), and several national groups have identified combinations of actions that they believe should receive the highest priority. The priority lists indicate expert opinion about the most needed actions and generally reflect the findings of the body of scientific evaluation research. The lists suggest that a consensus exists on the need for certain measures. NHTSA, on the basis of the scope of federal government responsibilities and capabilities, has identified four strategies for special promotion through its technical assistance and coordination activities (NHTSA 2007a): • High-visibility enforcement, • Support for prosecutors and DWI courts, • Medical screening and brief intervention for alcohol abuse problems, and • Enactment of primary seat belt laws. NHTSA’s activities with regard to impaired driving are described in the section below on federal responsibilities. NHTSA’s high-priority strategies are consistent with the recommended actions to reduce alcohol-impaired driving of the Task Force on Community Preventive Services, a nongovernmental expert panel convened by the Centers for Disease Control and Prevention that publishes public health policy recommendations founded on rigorous reviews of research on effectiveness. Addressed to state and local governments and community organizations, the task force’s recommendations for measures that are not already generally applied are as follows (Task Force on Community Preventive Services n.d.): • Sobriety checkpoints: A sobriety checkpoint is a site where police systematically stop drivers, look for signs of impairment, and administer a breath test when there is reason to suspect impairment. 

102 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations • Intervention training programs for servers of alcoholic beverages: These programs teach servers ways to prevent intoxication among their patrons (for example, by delaying or denying service). • Mass-media campaigns: The evidence for effectiveness applies mainly to media campaigns that use pretested messages; attain high exposure through paid advertising; and complement local-level, high-visibility enforcement. • School-based instructional programs aimed at discouraging students from riding with drinking drivers. • Multicomponent intervention with community mobilization: This strategy involves recruiting participation of community coalitions or task forces in the design and execution of interventions such as those listed above. • Ignition interlocks: An alcohol ignition interlock is a device installed in a vehicle that prevents a driver with BAC above a preset level from starting the engine. Use of an interlock may be required by the court as a condition of probation for an impaired-driving offender. The task force also recommends retention of three laws that are already in force in all states: the 0.08 percent BAC limit, lower legal BAC limits for young or inexperienced drivers, and the minimum legal drinking age of 21 years. The task force’s research review found that these three laws are effective in reducing motor vehicle occupant injuries. Finally, the National Transportation Safety Board has published a list of recommended actions to reduce fatalities and injuries involving “the hard core drinking driver,” a category defined to include repeat offenders and high-BAC offenders. The recommendations include special penalties for high-BAC offenders, lower BAC limits for repeat offenders, administrative license revocation, sobriety checkpoints, vehicle sanctions including impoundment and interlocks, alternatives to confinement involving strict supervision, restriction of plea bargaining, and elimination of diversion programs (NTSB 2000). Reviews of evaluation studies have concluded that random sobriety checkpoints and checkpoints conducted under U.S. rules [which allow police to stop all vehicles (or vehicles selected according to some rule, such as every third vehicle) at a preannounced location and time period, observe their drivers, and administer sobriety tests to those that show signs of intoxication] were both effective in reducing alcohol-related fatal crashes. Furthermore, U.S. methods, applied with sufficient intensity and efficiently managed, can equal the effectiveness of random testing enforcement (Shults et al. 2001, 76; Elder et al. 2002). Research evidence also indicates that lowering the U.S. BAC limit from 0.08 percent to the 0.05 percent limit prevailing elsewhere would be an effective safety measure. A comprehensive review of research studies concluded that lowering the BAC limit from 0.10 to 0.08 in the United States reduced alcohol-related crashes and casualties. The review concluded that lowering the limit from 0.08 to 0.05 in other countries reduced alcohol-related fatalities and that this effect cannot be accounted for solely by changes in publicity or enforcement that were introduced in some countries simultaneously with the lowering of the BAC limit. Research has found that crash risk is substantially higher for drivers with BAC of 0.05 than for drivers with 0.00 BAC and that lowering the limit to 0.05 can reduce the incidence of impaired driving at much higher BAC levels (i.e., at BAC over 0.15 percent). The authors conclude that the introduction of more stringent laws serves as a general deterrent to drinking and driving (Fell and Voas 2006). 

Case Studies of Safety Interventions 103 Implementation and Obstacles The federal requirements described in the following section have contributed to a progressive strengthening of state laws with regard to the legal drinking age, BAC limits, and other alcohol control measures. IIHS rates the adequacy of the laws of all the states concerning alcohol- impaired driving. In the 2009 survey, 19 states earned an overall “good” rating for their laws and one state was rated as “poor.” The remainder received “fair” or “marginal” ratings. In comparison, 16 states were rated good and one poor in 2006, and in the 2000 survey eight were good and five poor. A good rating means the state has a 0.08 percent BAC limit, has an administrative license revocation law and a “zero tolerance” law (imposing a stricter impaired- driving standard on new drivers) that IIHS judges to be effective, and allows sobriety checkpoints. A poor rating means that no more than one of these laws is adequate (IIHS 2009a; IIHS 2006; IIHS 2000). State legislative actions on impaired driving are monitored by the National Conference of State Legislatures (NCSL). In the 2009 review, NCSL reported that 229 impaired-driving bills were introduced in legislatures in 2009 and that 25 states enacted laws relating to impaired driving (Savage et al. 2010). Contents of legislative activity reported by NCSL included the following: • High-BAC countermeasures: By 2009, 43 states and the District of Columbia had laws providing stronger sanctions for high-BAC offenses (offenses in which the driver has BAC above a threshold ranging from 0.15 to 0.20 percent). Two states enacted high-BAC laws in 2009. • Ignition interlocks: As of November 2009, nine states required ignition interlock devices on the vehicles of all convicted drunk drivers, including two states that passed such laws in 2009. [The total rose to 12 states in 2010 (GHSA n.d. a).] Thirty-two states considered some form of ignition interlock legislation during the year. Much less information is available on the level of effort the states devote to implementation of countermeasures than on the laws in place in each state. The NHTSA report that presented the categorization of countermeasures summarized above (Hedlund et al. 2007) also attempted to judge the extent of use of each countermeasure, with ratings ranging from “high use” to “low use.” Among the effective measures with low or unknown use are DWI courts (low), citizen monitoring of court performance in impaired-driving cases (low), and passive breath sensors (unknown). Sobriety checkpoints are rated “medium use” on the basis of the number of states that allow checkpoints; however, it is noted that few states make regular use of checkpoints and that a 2003 survey found only 11 states that conduct checkpoints on a weekly basis (Hedlund et al. 2007, 1-15). In 10 states (Idaho, Iowa, Michigan, Minnesota, Oregon, Rhode Island, Texas, Washington, Wisconsin, and Wyoming), sobriety checkpoints are not permitted under state law, and two states (Alaska and Montana) never use checkpoints as a matter of policy (MADD n.d.). 

104 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Federal Government Engagement Authority for regulation of traffic and of alcohol rests with the states and local governments. Therefore, federal responsibility for drunk driving prevention is limited. However, federal laws and programs have significantly influenced state practices. Federal involvement has taken three forms: mandates requiring the states to enact certain restrictions as a condition for receiving federal funding; incentive grants to fund state safety programs that meet federal standards; and NHTSA programs that aim to provide leadership, coordination, and technical support for state alcohol safety initiatives. Mandates The 1998 federal surface transportation aid legislation (the Transportation Equity Act for the 21st Century) penalized any state that did not enact a repeat intoxicated-driver law (providing stronger penalties for repeat offenders) and an open container law (forbidding possession of an open alcohol container in a vehicle) satisfying federal criteria. States without such laws lose up to 3 percent of their federal highway construction aid funding. The lost construction funding is transferred to the state’s federal highway safety funding and may be used only for drunk driving prevention programs or road hazard elimination. In 2000, Congress enacted a provision requiring each state to enact a 0.08 percent BAC limit or lose up to 8 percent of its federal aid construction funds (GHSA n.d. b; Thiel 2003). Forty-three states complied with the federal repeat offender law mandate and 43 with the open container law mandate by 2010; many of these state laws were enacted after imposition of the federal requirements. All states now have a 0.08 percent BAC limit law. Before 1998, 0.10 percent was the limit in most states and only 16 states had 0.08 percent BAC laws (GHSA n.d. a; Thiel 2003). Reducing the limit nationwide to 0.08 has reduced the gap between regulations in the United States and most of the other high-income countries. The 1998 and 2000 laws follow the precedent of 1984 federal legislation that required all states to enact a minimum legal drinking age of 21 years or lose a portion of federal highway aid. By 1987, all states were in compliance (Task Force on Community Preventive Services 2005, 350). Incentive Grants Federal grants specifically to promote and fund programs aimed at drunk driving have been provided to the states since at least the 1980s. The most recent federal surface transportation aid legislation [the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU)] authorized an average of $129 million annually over 2006–2009 in the Alcohol-Impaired Driving Countermeasures Incentive Grants Program, for distribution by NHTSA by a formula (depending on state population and road miles) among all states that meet certain qualifications. This amount was more than three times the authorization in the previous federal-aid program ($220 million over 6 years). States could qualify in 2009 if they operated at least five of the following eight programs: • A high-visibility impaired-driving enforcement program, 

Case Studies of Safety Interventions 105 • An outreach program to educate prosecutors and judges on repeat offender prosecution, • A program to increase the fraction of drivers involved in fatal crashes that are tested for BAC, • A law that imposes stronger penalties on drivers with BAC exceeding 0.15 percent, • A rehabilitation program or oversight by a special DWI court for repeat offenders, • An underage-drinking prevention program, • An administrative license suspension or revocation law for offenders, and • Provision for applying the fines paid by offenders to fund local government impaired- driving prevention. States may also qualify if they have relatively low alcohol-related fatality rates, and a separate grant program is available to the 10 states with the highest alcohol-related fatality rates in a year (NHTSA n.d.; Savage et al. 2007). SAFETEA-LU also authorizes grants in several traffic safety categories with more general eligibility criteria, which the states may use to fund drunk driving prevention. These include the State and Community Highway Safety Grants, Information System Improvement Grants, and High Visibility Enforcement Grants, which are authorized, in total, at about $290 million annually (NHTSA n.d.). Guidance and Coordination NHTSA spends about $40 million annually in technical assistance and demonstration activities promoting alcohol and drug countermeasures; vehicle occupant protection; traffic law enforcement; emergency medical care systems; traffic records; and safety of motorcyclists, bicyclists, pedestrians, pupils, and younger and older drivers (USDOT 2007). NHTSA has identified four strategies that it views as crucial for reducing alcohol-related traffic deaths and that it promotes through its technical assistance and leadership activities: high-visibility enforcement, support for prosecutors and DWI courts, medical screening and brief intervention for alcohol abuse problems, and enactment of primary seat belt laws (NHTSA 2007a). High-visibility enforcement initiatives are enforcement crackdowns, either of short duration or sustained, aimed particularly at enforcing drunk driving and seat belt laws and coinciding with media publicity. NHTSA’s role has been to organize multijurisdictional, high- visibility enforcement efforts to take advantage of the economies of scale and enhanced impact of regional and national crackdowns. The slogan of the current campaign is “Drunk Driving. Over the Limit. Under Arrest.” Ten thousand police agencies nationwide have committed to coordinating enforcement crackdowns through this program, and NHTSA is assisting with media publicity and technical aid. NHTSA reports that evaluation of an earlier phase of the high- visibility enforcement initiative showed that it produced a sustained reduction in alcohol-related fatalities (NHTSA 2007a, 4). NHTSA promotes special training for prosecutors handling impaired-driving cases and encourages establishment of special state DWI courts to hear cases and monitor compliance with sentences, in order to improve the effectiveness of adjudication of impaired-driving cases. The initiative is needed because lack of capacity in the court system to prosecute offenders successfully and to oversee sanctions has undermined enforcement and encouraged recidivism. 

106 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations NHTSA’s involvement has been to provide grant funding of state Traffic Safety Resource Prosecutor positions and technical assistance and training for prosecutors and DWI courts. Screening and brief intervention can be performed by doctors during emergency room visits or checkups to identify patients with alcohol use problems and to encourage treatment or other action. NHTSA reports that evidence shows that the technique reduces impaired driving among problem drinkers (NHTSA 2007a, 7). NHTSA’s involvement has been in working with other federal agencies and medical organizations to promote screening and brief intervention as routine medical practices. NHTSA includes enactment of primary seat belt laws among its four crucial anti–drunk driving strategies because fatally injured drunk drivers are far less likely to have been wearing seat belts than fatally injured drivers with zero BAC. Stronger enforcement of seat belt laws would therefore be expected to reduce alcohol-related motor vehicle deaths. NHTSA research demonstrating the benefits of seat belts and of primary seat belt laws and its information programs that publicize these benefits aid efforts to enact state primary seat belt laws. Concluding Observations After at least 15 years of progress, in the past decade almost no reduction has been achieved in the annual numbers of fatalities in alcohol-related crashes in the United States. Several of the benchmark countries, including Great Britain, Australia, and Sweden, have experienced similar slowdowns or reversals of progress in reducing alcohol-related traffic fatalities. In some countries these developments correlate with slackening of enforcement efforts or increases in alcohol consumption; however, the causes are not well understood, and other factors, for example demographic trends, may be important. Data on the extent and patterns of impaired driving in the United States are incomplete and of uncertain reliability. Improved data could help in understanding the causes of the recent slowdown in progress and in design of more effective programs. Several countermeasures that have proved effective and are regularly used in some jurisdictions in the United States remain little used in much of the country. Examples are sobriety checkpoints, close monitoring of offenders, and ignition interlocks. Federal involvement in prevention of alcohol-impaired driving has had mixed success. Federal mandates have caused many states to strengthen anti–drunk driving laws, but NHTSA technical assistance and coordination programs operate with limited resources. The impact of federal grants for state alcohol programs is unknown. Although differences in measurement methods complicate comparisons, Germany, Great Britain, Sweden, and Australia all appear to have attained lower rates of alcohol-involved traffic fatalities, per vehicle kilometer of travel and as a fraction of all fatalities, than the United States. Getting progress started again in the United States apparently will require more widespread and systematic application of the proven countermeasures and greater coordination of strategy among law enforcement agencies, the court system, and public health programs aimed at alcohol abuse. The federal government may have a role in providing leadership for such efforts. All of these actions will require increases in funding. In countries that have introduced sustained, high-frequency programs of random sobriety testing, including Australia, Finland, and France, reductions of 13 to 36 percent in the frequency of alcohol-involved fatal injury crashes have been achieved. Evaluations of intensive campaigns of selective testing at sobriety checkpoints in U.S. jurisdictions (following procedures now legal 

Case Studies of Safety Interventions 107 in most states) have reported reductions of 20 to 26 percent in alcohol fatal injury crashes (Shults et al. 2001, 76; Fell et al. 2004, 226). In the United States in 2008, 12,000 persons were killed in crashes involving a driver who was alcohol-impaired (NHTSA 2009c, 113). Therefore, widespread implementation of sustained, high-frequency sobriety testing programs in the United States could be expected to save 1,500 to 3,000 lives annually. SPEED CONTROL The first four sections below describe the relationship between speed control and crash and casualty risk, summarize U.S. trends in speed and speed enforcement, compare U.S. speed trends and enforcement practices with those of the benchmark countries, and describe examples of recent U.S. speed control initiatives. Summary observations are presented in the final section. Value of Speed Control in Reducing Crash Risks The Governors Highway Safety Association (GHSA), summarizing a survey of the states on speeding enforcement, reports that “states are becoming increasingly concerned that gains made in the areas of safety restraint usage and impaired driving have been offset by increased fatalities and injuries due to higher speeds” (GHSA 2005, 5). In contrast, in several of the countries that are making the greatest progress in highway safety, speed control is one of the interventions receiving the greatest attention and resources. If speed control is weakening in the United States, this trend may explain part of the safety performance gap between the United States and other countries. A 2006 report of the Organisation for Economic Co-operation and Development (OECD), the product of an international expert panel, expresses the high priority that many safety professionals place on speed control (OECD and ECMT 2006, 3): Speeding . . . is the number one road safety problem in many countries, often contributing to as much as one third of fatal accidents and speed is an aggravating factor in the severity of all accidents. . . . Research indicates that co-ordinated actions taken by the responsible authorities can bring about an immediate and durable response to the problem of speeding. Indeed, reducing speeding can reduce rapidly the number of fatalities and injuries and is a guaranteed way to make real progress towards the ambitious road safety targets set by OECD/ECMT countries. . . . Speed management . . . should be a central element of any road safety strategy. The two subsections below summarize current understanding of the effect of speed on crash and injury risk and the effect of regulation and enforcement on speed. Effect of Speed on Crash and Injury Risk Despite the assurance of the OECD statement above, researchers have found that sorting out the effects of speed and speed controls on overall crash and injury risk is a difficult task. For example, one U.S. research review concluded: “Speed has a demonstrated negative effect on 

108 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations safety in that it increases the severity of accidents. While it is suspected that speed may also contribute toward the incidence of accidents, there are so many other factors that are also affected by speed, and which simultaneously affect safety, that it is difficult to distinguish the effect of speed on the occurrence of an accident” (Wilmot and Khanal 1999, 329). Similarly, a Transportation Research Board (TRB) committee that reviewed speed management practices found that “drivers’ speed choices impose risks that affect both the probability and severity of crashes. Speed is directly related to injury severity in a crash. . . . [T]he strength of the relationship between speed and crash severity alone is sufficient reason for managing speed. . . . Speed is also linked to the probability of being in a crash, although the evidence is not as compelling because crashes are complex events that seldom can be attributed to a single factor” (TRB 1998, 4). In the United States, the safety effects of speed control became especially controversial during the term of the 55-mph National Maximum Speed Limit (NMSL) (in effect, with modifications, from 1974 to 1995). One prominent study concluded that, in states that raised the speed limit on rural Interstates, as Congress permitted in 1987, statewide fatalities were reduced by 3 to 5 percent. The authors attributed the reduction to attraction of traffic from less safe roads to the Interstates and the freeing of police to patrol the more dangerous roads rather than the Interstates (Lave and Elias 1994). The TRB speed limit committee concluded that, after the 1987 change in the law, “in the immediately following years, most states that raised limits observed increases” in speeds and speed dispersion on roads where limits were raised and that “[t]hese speed changes were generally associated with statistically significant increases in fatalities and fatal crashes on the affected highways” (TRB 1998, 5). That committee’s review of studies of the effects of the 1995 repeal of the NMSL showed the same results; however, the committee acknowledged that systemwide safety effects could be negative but had not been adequately studied. Notwithstanding the past controversies over the effect of speed on risk, present speed control programs are based on the assumption that average speed is directly related to injury crash frequency on a road and, therefore, that reducing average speed by enforcement will reduce injuries and deaths. A review of estimates of the speed–crash relationship concluded that the best description of the relationship, as a rule of thumb, is that “a 1 percent increase in speed results approximately in 2 percent change in injury crash rate, 3% change in severe crash rate, and 4% change in fatal crash rate” and that “an increase in average speed was found to increase the risk of a crash more on minor than on major roads” (Aarts and van Schagen 2006, 223, 220). Effectiveness of Speed Regulation and Enforcement The accepted view of conventional practice with regard to speed limits and speed control is that “generally, motorists do not adhere to speed limits but instead choose speeds they perceive as acceptably safe. . . . The impact of law enforcement on compliance with speed limits is, generally, limited and transitory” (Wilmot and Khanal 1999, 315, 320). Similarly, an essay on speed management published by the AAA Foundation for Traffic Safety concludes that “current methods for controlling speed are virtually powerless in the face of this [U.S.] speeding culture” (Harsha and Hedlund 2007, 1). However, experience (e.g., in France and Australia, as described in Chapter 3) has demonstrated that the combination of appropriately determined limits, persistent and well- managed enforcement with adequate resources, and public outreach can effectively control 

Case Studies of Safety Interventions 109 speeds. The necessary elements of such a program, according to the OECD speed management report, are as follows (OECD and ECMT 2006, 3): • Targeted education and information to the public and policy makers. • Assessments of appropriate speed and a review of existing speed limits. . . . • Infrastructure improvements which are aimed at achieving safe, ‘self explaining’ roads [i.e., roads with features like intersection roundabouts that naturally induce drivers to operate their vehicles in a safer manner]. . . . • Sufficient levels of traditional police enforcement and automatic speed control, encompassing all road users. . . . The recommendations of the TRB speed limit committee are consistent with the OECD recommendations. The committee advised the following (TRB 1998, 8–13): • Establishment of limits that are reasonable for the road and that are enforceable (i.e., setting limits with primary reference to actual speeds; a well-accepted guideline is that the limit should equal the actual 85th percentile speed on the road, with adjustments for special conditions affecting speed risk); • Sustained long-term commitment to conventional police enforcement, use of automated enforcement, and judicious use of traffic calming; and • Use of public information campaigns. A final set of recommendations for speed control programs in the United States is presented in the essay from the AAA Foundation cited above. The authors argue that two strategic elements will be necessary in a successful nationwide program to reduce speeding: first, political leadership at the federal, state, and local levels, starting with congressional action, to establish speed control as a high-level safety priority; and second, a staged approach to speed control campaigns that starts with campaigns to eliminate speeding in specific locations and situations where public support already exists and where evidence indicates that speeding is a specially significant risk factor. Such initial efforts will increase public awareness and support for expanding speed control (Harsha and Hedlund 2007). Cost-Effectiveness of Speed Control The speed control programs in France, Australia, Sweden, and the United Kingdom described in Chapter 3 all rely heavily on automated enforcement (i.e., detection and identification of speeding vehicles by means of automated cameras and speed-measuring devices installed in the roadway). In the United Kingdom (as noted in Chapter 3), 90 percent of all speed offenses cited are identified by the camera system. Chapter 3 also described the dramatic reduction in speeding reported in France (a two-thirds reduction in vehicles traveling 10 km/h or more over the limit from 2000 to 2008) since expansion of automated enforcement and the substantial systemwide safety benefits that French and Australian evaluations attribute to speed control, as well as the smaller benefits estimated in Sweden and the United Kingdom. Such a large disparity in the cost of application between the United States and the benchmark countries probably does not apply to any of the other countermeasures that are prominent in the benchmark countries’ safety programs. In the United States, automated 

110 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations enforcement is rare and politically difficult to impose. Conventional U.S. speed enforcement tactics are labor-intensive and expensive. Therefore, despite the international research evidence that speed control is an effective safety measure, it is necessary to consider whether U.S. speed control methods are cost-effective. Within a state safety program, speed control would be cost- effective if the resources required (including program funds and police and other agency personnel time) to produce safety benefits could not be used to produce greater benefits in any alternative application. In a broader context, assessment of the cost-effectiveness of speed control would take into account the time cost to travelers of slower travel speeds, as well as the costs to safety agencies. The most intensive speed enforcement tactic commonly used in the United States is the high-visibility enforcement campaign, often targeting other forms of aggressive driving (e.g., illegal passing, tailgating, and weaving) as well as speeding. NHTSA’s review of countermeasure effectiveness, Countermeasures That Work, defines the tactic as follows: “In the high-visibility enforcement model, law enforcement targets selected high-crash or high-violation geographical areas using either expanded regular patrols or designated aggressive driving patrols. . . . to convince the public that speeding and aggressive driving actions are likely to be detected and that offenders will be arrested and punished. . . . Enforcement is publicized widely” (Hedlund et al. 2009, 3-13). The speed management volume of the American Association of State Highway and Transportation Officials (AASHTO) strategic planning safety guide (NCHRP Report 500) states that “consistent speed enforcement can be effective in deterring drivers from speeding” (Neuman et al. 2009, V-30). However, the research cited there does not quantify the relationship between enforcement and speed and does not address cost-effectiveness. Countermeasures That Work concludes that “taken together, the evaluation evidence suggests that high-visibility, aggressive driving enforcement campaigns have promise but success is far from guaranteed. . . . As with alcohol-impaired driving and seat belt use enforcement campaigns, the main costs are for law enforcement time and for publicity.” Research support cited is from NHTSA demonstration projects, which were inconclusive on the whole. The review rates costs as “high” (Hedlund et al. 2009, 3-13–3-14). The NHTSA speed management demonstrations described in Chapter 3 mostly attained small reductions in speed, which presumably were transient; however, the scale of the demonstrations was such that they may not be a fair indication of the effectiveness of high- visibility enforcement. The demonstration evaluations did not provide cost information and therefore give no indication of cost-effectiveness. The Minnesota speed management demonstration, described later in this section, appears to be the best U.S. evidence that speed management using conventional enforcement techniques can produce worthwhile safety results for an extended period over major portions of a road system at a practical cost. Reliable assessment of the cost-effectiveness of speed control or of other countermeasures is not possible in the United States today because most enforcement and safety agencies do not systematically maintain data on level of enforcement effort or on intermediate outputs (i.e., speed trends correlated with enforcement effort). The NHTSA speed management uniform guideline (described in Chapter 3) recommends collection and use of these data to evaluate speed management programs. 

Case Studies of Safety Interventions 111 Trends in Speed, Speed-Related Crashes, and Speed Enforcement The subsections below summarize available information on trends in speed and speeding, speed- related crashes, and speed control enforcement effort to determine whether there is any evidence at the national level that speed management is becoming more intense or more effective. Speeds and Speeding Programs to compile summary data on speed trends are an indication of management attention and interest. The speed management programs in other countries described in Chapter 3 rely on close monitoring of speeds to measure performance, to direct resources, and to communicate the effectiveness of the program to political officials and the public. Speed trends also provide a test of the GHSA report’s conclusion cited above that speed is a worsening safety problem and that gains from successful safety interventions have been offset. The Federal Highway Administration (FHWA) published data from the states on average speeds and speed distributions for various road classes from the 1940s until 1993 (Figures 4-2 and 4-3). After the repeal of the NMSL and the associated state speed data reporting requirements, FHWA ceased compiling the data; consequently, no current aggregate national summary of speed trends exists. The reliability of the state-reported data, particularly in the later years of the NMSL, is suspect. The FHWA data show gradually increasing speeds and frequency of speeding from the 1970s through the early 1990s. A 2006 survey of the states conducted by NHTSA found only six states that published statewide speed surveys on the Internet and 30 that reported that they systematically monitor speeds (OECD and ECMT 2006, 255). Figures 4-4 and 4-5 show speed trends in Minnesota for 1995–2002 and in Washington for 2000–2010, respectively. In Minnesota, 85th percentile speeds increased by 4 to 5 mph on freeways and other rural divided highways in the period shown. Speed limits were increased by 5 mph on rural and urban freeways and by 10 mph on other rural divided highways in 1997. Speeds on road classes where the limits were not changed showed no trend. In Washington, average speeds on Interstates and other arterials and the fraction of vehicles on Interstates exceeding the limit show no clear trend over the 2000–2010 period, although speeding on non-Interstate arterials appears to be increasing. The fragmentary data available do not demonstrate that speed is a growing problem. However, traffic flow studies show that on roads with heavy traffic, for a given road class and traffic volume, drivers travel faster today on average than they did in past decades. That is, drivers slow down less on a crowded road than they formerly did (TRB 2003, 55). This change in driver behavior may be affecting the relationship between speed and crash and casualty risk. Shorter following distances may increase risk, but declining speed variance would tend to reduce risk. Crashes and Fatalities Attributed to Speed NHTSA publishes data on the numbers of fatalities and fatal crashes that are speeding related (Box 4-1). A speeding-related crash is defined as one in which “the driver was charged with a speeding-related offense or . . . an officer indicated that racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in the crash” (NHTSA 2007d, 1). (Before 2002, NHTSA used a different definition.) NHTSA-reported speeding-related fatalities 

112 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations were 31 percent of total fatalities in 2008; the fraction declined from the 1980s through the mid- 1990s and since has fluctuated (Figure 4-6). This percentage often is presented as an indicator of the magnitude of the speeding problem’s contribution to highway fatality risk (e.g., NHTSA 2007d) and might be taken as an index of the success of speed management practices (e.g., to test the GHSA statement that speed is a growing risk factor). However, the significance of the statistic is not evident. The prevalence of crashes meeting NHTSA’s definition of “speeding-related” cannot by itself reveal the numbers of fatalities that could be avoided if speeding were reduced because, in the NHTSA definition, every crash that involves a vehicle that is speeding is “speeding-related.” Also, the large and seemingly patternless variations among states in the speeding-related share of fatalities that NHTSA reports [from over 45 percent in five states (Alaska, Pennsylvania, Hawaii, Alabama, Missouri) to under 12 percent in three (New Jersey, Arkansas, Iowa) in 2008 (see Figure 4-7)] suggest that some factor such as variability in police crash-reporting procedures may be distorting the measure. The downward trend in the measure may reflect the raising of speed limits during the 1980s and 1990s. Measuring how speed affects crash risk requires exposure data (i.e., data on average speed and the speed distribution for all vehicles on the road), which generally are not available in the United States. FIGURE 4-2 Average speed on all U.S. highways, 1940–1993. (SOURCE: Wilmot and Khanal 1999, from data published in FHWA’s Highway Statistics series; copyright, Taylor and Francis; used with permission.) 

FIGURE 4-3 Speed trends on rural Interstate highways, 1965–1995. 

80 75 85th percentile speed (mph) Rural freeway 70 Rural divided highway Urban freeway Rural 2-lane 65 Urban divided highway 60 55 1995 1996 1997 1998 1999 2000 2001 2002 FIGURE 4-4 Speed trends on Minnesota roadways, 1995–2002. [SOURCE: Minnesota Department of Transportation (http://www.dot.state.mn.us/speed/index.html).] 

80 75 70 65 70mph IS, avg. speed mph or percent 70mph IS, 85th %ile speed 60 70mph IS, % ≥ limit 60mph non-IS, avg. speed 55 60mph non-IS, 85th %ile speed 60mph non-IS, % ≥ limit 50 45 40 35 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 FIGURE 4-5 Speed trends, 2000–2010, Washington State. Key: 70 mph IS = Interstate highway with 70-mph speed limit; 60 mph non-IS = non-Interstate arterial with 60-mph speed limit. Data are for January–March of each year. (Source: Washington State Department of Transportation quarterly speed reports.) 

116 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations P ercent of annual fatalities that are speeding-related, 1983-2008 38 37 36 35 34 percent 33 32 31 30 29 28 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 year FIGURE 4-6 Percentage of annual fatalities that are speeding related, 1983–2008. (SOURCES: NHTSA 2005a; NHTSA 2007b; NHTSA 2007e; NHTSA 2008a; NHTSA 2009c.) In comparison with the NHTSA statistic that 30 percent of fatalities are speeding-related, an estimate based on crash investigations found speeding to be a “causal factor” in 19 percent of a sample of crashes in 1996–1997 (Hendricks et al. 2001). On the other hand, it has been reported that a common view among law enforcement officers is that speeding is involved in almost all serious crashes (Harsha and Hedlund 2007, 259). Enforcement Effort Spending for highway law enforcement and safety programs has been fairly stable in recent decades and has been rising in the past 10 years (Figure 4-8), per vehicle mile of highway travel and as a share of total noncapital highway spending, according to the FHWA national highway finance summaries. [FHWA defines this spending category as follows: “Highway law enforcement and safety expenditures are: traffic supervision activities of State highway patrols; highway safety programs including driver education and training, motorcycle safety; vehicle inspection programs; and enforcement of vehicle size and weight limitations. General police expenses associated with drug interdiction, criminal investigation, and security activities are excluded” (FHWA 2006, IV-7).] In a survey conducted for the 1998 TRB speed limit study, most states reported that from 20 to 50 percent of total state police officer time spent on traffic enforcement is devoted to speed enforcement (TRB 1998, 146–147). 

Percent of trafic fatalities that are speeding-related by state, 2008 60 50 40 percent 30 20 10 0 TX TN IN ID IL CT MT VT UT AZ MI IA RI HI NJ AR OH ND NH MN OR SD MD NC DC SC FL AL CO MO NM MS NE KY GA MA KS LA NV OK ME DE VA CA NY PA AK WI WV WA WY FIGURE 4-7 Percentage of fatalities that are speeding related, by state, 2008. 

118 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Highway law enforcement & safety expenditures, U.S. total, as percent of total noncapital expenditures, 1980-2008 30 25 20 percent 15 10 5 0 1980 1985 1990 1995 2000 2005 2008 Constant-dollar enforcement & safety expenditures, U.S. total, per million VMT, 1980- 2008 (year 2000 dollars) 5000 4500 4000 3500 $/million VMT 3000 2500 2000 1500 1000 500 0 1980 1985 1990 1995 2000 2005 2008 FIGURE 4-8 (top) Highway law enforcement and safety expenditures, U.S. total, as percentage of total noncapital expenditures, 1980–2008; (bottom) constant-dollar enforcement and safety expenditures (2000 dollars), U.S. total, per million vehicle miles traveled, 1980–2008. Price index is gross domestic product implicit price deflator from Bureau of Economic Analysis. (SOURCES: FHWA 1997, Tables HF-210, VM-201; FHWA 2001, Tables HF-10, VM-1; FHWA 2006, Tables HF-10, VM-1; FHWA 2010, Tables HF-10, VM-1.) 

Case Studies of Safety Interventions 119 Comparisons with Benchmark Countries The 2005 GHSA state survey on speed management asked about speed limits, availability of speed and speed-related crash data, and enforcement and other speed control efforts. The following are among the findings: • Few states were able to cite a state-level program focusing on speed control (Washington and Arizona were exceptions). Most responded that speed control was one of several risks addressed in state Selective Traffic Enforcement Programs (STEPs). A STEP is a high-visibility, short-duration intensive enforcement and public awareness campaign targeting specific high-risk behaviors in a specific area. The technique has been most commonly applied in promoting seat belt use but has not commonly been used against speeding or aggressive driving (Nerup et al. 2006, v; Nichols et al. 2007, 1; Hedlund et al. 2007, 3-8). • Most states were not able to isolate federal highway safety grant funds received that were allocated specifically to speed control. • Thirty-one states reported maintaining speeding-related citation or conviction data in a statewide database, although some include only state police–issued citations. • In response to a question asking about the impact of speeding or aggressive driving programs in the past 2 years, states that responded reported trends in statewide speeding-related crashes or fatalities or in total highway fatalities. No state reported results of a scientific evaluation of speed control programs. These responses lend support to the conclusion of the AAA Foundation essay cited above that speed control has not attained high priority in safety programs. Speeding is common in most high-income countries, according to a 2006 OECD survey (OECD and ECMT 2006, 256–259). The fraction of drivers exceeding the limit on undivided major highways in several countries is reported as follows: Country and Limit Percentage Austria, 100 km/h 47 Canada, 100 km/h 15 to 76, depending on province Ireland, 60 mph 30 Korea, 85 km/h 85 Netherlands, 100 km/h 20 Poland, 100 km/h 42 Portugal, 90 km/h 65 Sweden, 110 km/h or lower 59 United Kingdom, 60 mph 10 United States, 65 or 55 mph (three states) 52 to 77 The United Kingdom, the Netherlands, and British Columbia claim substantial compliance with speed limits on this road class; however, the high rates of speeding that are typical of the United States are observed in several other countries. The speed management programs in France, Australia, Sweden, and the United Kingdom, described in Chapter 3, have produced speed reductions that can be linked with reductions in crashes and fatalities. These programs are of long duration, with enforcement and information campaigns extending over a period of years; they are applied over extensive portions of the 

120 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations national or state road systems; and they rely on automated enforcement. There appears to be no U.S. speed management program of comparable scale. In France, as part of the nationwide traffic safety initiative launched in 2002, an extensive automated enforcement system was installed. Speeding citations increased 22 percent from 2000 to 2003 and then doubled from 2003 to 2004, the result of the automated enforcement system. The total of license point penalties assessed increased 44 percent in 2004 compared with 2003, and license suspensions increased 87 percent, largely the result of speed enforcement (OECD and International Transport Forum 2006; ONISR 2005). Speed data show the results of stepped- up enforcement. The percentage of light vehicles in free-flowing traffic exceeding the speed limit by more than 10 km/h has declined each year, from 36 percent in 2001 to 16 percent in 2006 and 12 percent in 2008 (ONISR 2006; ONISR 2009b). The national safety statistical agency has estimated that 75 percent of the total reduction in casualties (fatalities plus injuries) from 2002 through 2005 can be attributed to speed reductions over the period (CISR 2006, 6). Annual fatalities declined 31 percent from 2002 to 2005. As noted in Chapter 3, this estimate is not derived from direct observation of the effect of reduced speeds on crashes on French roads during the period of increased enforcement. In the state of Victoria, Australia, in 2000–2004, new laws lowered the urban speed limit, greatly increased the density of the speed camera system first set up 10 years earlier, and increased penalties for speeding. Anti–drunk driving enforcement was strengthened at the same time (Johnston 2006, 10–11). Implementing the new 50-km/h speed limit in urban areas is a major component of the strategy. Average speeds on all types of roads were observed to decline. Fatalities have declined, and the patterns of decline reportedly indicate that speed reduction has been a major contributor, although the relationship has not been quantitatively demonstrated (OECD and ECMT 2006, 11). As Chapter 3 described, road officials in Sweden and the United Kingdom attribute more modest safety benefits to current speed control programs than do the French and Australian authorities. One source of this difference may be that speed compliance was better in Sweden and the United Kingdom before inauguration of the automated systems, but the available information is not sufficient to account for the difference definitively. Examples of U.S. Speed Control Programs The first subsection below describes the federal government’s involvement in speed control through the NMSL of 1974–1995. The second presents examples of present state and local speed management programs. National Maximum Speed Limit The 1974–1995 NMSL is a well-documented example of speed management as a political issue. The NMSL was undertaken with high-level political leadership and enjoyed initial public acceptance, yet it quickly lost support as benefits dwindled and costs became apparent, and eventually it failed. Implementation of the NMSL departed in several respects from the speed management practices recommended in the OECD, TRB, and AAA Foundation reports cited above: limits were not set with reference to actual speeds, and local risk factors and enforcement practices were dictated by federal compliance requirements rather than by safety considerations. 

Case Studies of Safety Interventions 121 The NMSL was initiated as a fuel conservation measure in response to the oil embargo of 1973. The president first appealed to the states to lower their limits in a national address in November 1973, and in January 1974 Congress enacted the requirement that states lower speed limits to 55 mph as a condition for receipt of federal highway funds. Originally a 1-year emergency measure, the NMSL was made permanent in 1975. Congress had been aware of possible safety benefits at the time of the original enactment, and an immediate apparent safety impact strengthened support for continuing the measure. Highway fatalities dropped 16 percent, from 54,000 in 1973 to 45,000 in 1974. (Vehicle miles traveled declined by 2.5 percent in 1974 as a result of recession and the oil embargo. Crashes and crash rates typically decline during recessions more rapidly than the long-term trend.) After the energy crisis subsided, efforts began in Congress to repeal or relax the limit. Western states especially saw the limit as unnecessarily burdensome. In 1987 states were allowed to raise the limit to 65 mph on rural Interstates, and in 1995 the NMSL was abolished (as a provision in the legislation that also removed federal penalties for failure to enact a state motorcycle helmet use law). Safety advocacy groups, for example, Public Citizen and IIHS, vigorously opposed repeal. Opponents of the NMSL pointed out the costs in time and convenience, the ambiguous data on safety benefits, and the misallocation of police enforcement efforts resulting from the federal requirement that states certify enforcement, and they argued that the states have the responsibility and the competence to manage their own road systems (Yowell 2005; Bashem and Mengert 1974; Kemper and Byington 1977; U.S. Department of Justice 1989). State and Local Speed Management Campaigns Three examples of speed management campaigns undertaken by local and state governments are described below. Each is a pilot program, that is, a test or a demonstration of techniques rather than a permanent program with a long-term charge and objectives. These pilots may be typical of recent speed control initiatives. Other state and local initiatives that involve data collection and evaluation may be in place as well, although NHTSA’s guidebook Countermeasures That Work observes that pedestrian safety programs similar to Heed the Speed and high-visibility speed and aggressive driving enforcement campaigns both are rarely used strategies (Hedlund et al. 2009, 3-13). Minnesota Speed Management Program The Minnesota Departments of Transportation and Public Safety conducted an evaluation of a trial of a speed management program in operation from September 2005 until August 2006 (Harder and Bloomfield 2007). The program had four elements: • Speed limits were raised from 55 to 60 mph on 850 miles of two-lane rural roads and urban expressways, which were selected on the basis of a design review. • State and local police increased speed enforcement on selected segments of the roads with increased speed limits and on selected segments of the state’s network of 1,870 miles of freeways and divided highways with limits of 65 or 70 mph. Stepped-up enforcement was organized in a series of 6- to 8-week waves, with periods of normal enforcement intervening. • An extensive publicity campaign was organized. 

122 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations • Evaluation was conducted by means of speed monitoring, before-and-after comparisons of the frequency of serious crashes, and opinion surveys. The cost of the 1-year trial was $3 million, of which $2.5 million was the cost of the increase in police enforcement hours. Additional enforcement of 22,000 person-hours (beyond normal levels) was applied (Harder and Bloomfield 2007, 5, 40, 41). The evaluation was motivated in part by proposals in the legislature to raise speed limits in the state. The department of transportation opposed general increases but supported selective increases on 55-mph roads with appropriate design. The evaluation showed that during the trial, average speeds were reduced on all categories of roads in the test, including roads on which the speed limit was raised and roads outside and within the zones of enhanced enforcement. The reduction was between 0.2 and 1.8 mph, depending on the road category and enforcement level. The frequency of speeding was substantially reduced. The frequency of serious crashes declined for all categories of road in the test compared with the average frequency during the same months in the preceding 5 years. The evaluation report recommends that the elements of the speed management program, including the evaluation, be continued and that funding be provided for the costs (mainly for increased enforcement). Phoenix “Heed the Speed” Program A pilot study was initiated in Phoenix and Peoria, Arizona, in 2002 to test and demonstrate methods of speed control in urban residential streets as a means of reducing crash risks and especially pedestrian injuries. Campaigns of 3 to 6 months were conducted in three neighborhoods, with a variety of countermeasures tested in various combinations, including traffic calming, pavement markings, intensive police enforcement, and several forms of publicity. The evaluation was designed and carried out by NHTSA with the participation of the local governments. Evaluation was by means of speed measurements and resident surveys. The pilot was judged a success because it demonstrated that neighborhoodwide speed reductions could be obtained. Average speed reductions of between 0.5 and 3.5 mph and reductions in the number of vehicles exceeding the speed limit by more than 7 mph of between 14 and 70 percent were observed, depending on the road (Blomberg and Cleven 2006). The pilot built on earlier pedestrian safety programs in Phoenix, and the techniques have seen further application in at least one Phoenix neighborhood (Gordon 2007). Scottsdale Loop 101 Speed Camera Demonstration and Arizona Photo Enforcement Program The city of Scottsdale, Arizona, in cooperation with the state, carried out a demonstration and evaluation of automated speed enforcement on a section of Arizona Highway 101 in 2006 and 2007. The city describes the project as the first U.S. test of photo enforcement on a freeway (City of Scottsdale n.d.). The demonstration used six fixed speed camera installations on the 8-mile portion of the highway within the city limits. The cameras were activated from February to October 2006 and from February to June 2007. Activation was accompanied by publicity. The evaluation concluded that camera enforcement reduced average speeds by about 9 mph, reduced the proportion of vehicles traveling 11 mph or more over the speed limit by 90 percent, and reduced the number of injury crashes by 28 to 48 percent. The estimated impact on user costs—travel time and crash costs—was positive. Travel time was reduced despite lower average speed 

Case Studies of Safety Interventions 123 because delay caused by crashes was avoided (Washington et al. 2007, 1–12). Impacts on agency traffic enforcement costs were not examined. The evaluation report proposes procedures to be followed in the design, evaluation, and deployment of speed cameras on freeways in the state (Washington et al. 2007, 131–134). After the demonstration, the city transferred the freeway enforcement program to the state. With a new state law as authorization, the Arizona Department of Public Safety expanded the photo enforcement network to include 36 fixed camera installations on freeways in the Phoenix and Scottsdale areas and 36 mobile photo enforcement units (Arizona Department of Public Safety n.d.). In 2010, after a change in administration in the state government, the department decided to discontinue the speed camera program. Automatic enforcement encountered political opposition, and at the time the program was discontinued opponents were organizing a ballot initiative to ban their use in the state (Newton 2010). Concluding Observations There are grounds for concern that speed management has been underemphasized in federal and state safety programs in comparison, for example, with the prominent and generally effective efforts devoted to drunk driving, seat belts, and vehicle crashworthiness and occupant protection. Some state officials believe that this underemphasis is one reason why U.S. crash and fatality rates show only small improvement compared with the progress in other countries in recent years. The lack of speed trend and related data in the United States and the lack of scientific evaluations of enforcement efforts are evidence that speed management has not received the highest priority. Intensive speed enforcement programs used elsewhere depend on data to determine whether goals are being met and to allocate enforcement resources. Rapid publication and dissemination of performance information are vital for communication with the public and political leaders and for accountability of the transportation and enforcement agencies. There appears to be no U.S. speed management program in operation today that is comparable in scale, visibility, and high-level political commitment with the most ambitious speed management programs in other countries. Such programs are of long duration, with enforcement and information campaigns extending over a period of years; they are applied over extensive portions of the national or state road systems; and they rely on automated enforcement (Table 4-3). The gap between U.S. practice and that in at least some other jurisdictions ought to raise the following questions for public officials responsible for the road system: Could the United States substantially reduce traffic injuries and fatalities by better speed management? If so, what kind of effort would be required, what are the best models of initiatives in the United States or elsewhere, and what are the obstacles to carrying out such programs? Other countries that introduced automated speed enforcement had to overcome public opposition on grounds similar to the objections that have been raised in the United States. U.S. safety program managers considering adoption of the methods of these countries can use the international experience to anticipate difficulties and to learn possible ways to address public concerns (Delaney et al. 2005). The Minnesota speed management trial described above attained average speed reductions on the order of 1 mph on rural roads and urban expressways and substantial reduction in the frequency of speeding by the use of available personnel (diverted to speed enforcement from other duties) and standard techniques. The review of research on the relationship between 

124 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations speed and crash risk cited above (Aarts and van Schagen 2006) concluded that a 1 percent reduction in average free-flow speed on a road system will yield a 4 percent reduction in crash fatalities; thus, a 1-mph reduction would reduce crashes by 6 percent. Application of this relationship, with the assumption that the Minnesota speed reduction results could be attained on half of all U.S. roads, leads to an order-of-magnitude estimate of a reduction in fatalities of 3 percent, or 1,100 lives annually. SEAT BELTS Regulations requiring vehicles to be equipped with seat belts and requiring occupants to use belts have been among the most beneficial safety interventions of the past three decades in the United States and all the benchmark nations. The sections below describe the effectiveness of seat belts in reducing traffic fatalities and of government actions promoting belt use, describe trends in use and in interventions in the United States, and compare U.S. experience and practices with those of benchmark countries. As a case study, this section describes only seat belt use and regulation; other kinds of occupant restraints, such as child safety seats and air bags, also have important safety benefits. TABLE 4-3 Speed Management in Benchmark Countries Compared with the United States France, United Kingdom, and Australia United Statesa Routine, low-level activity; Management and planning Focused program with goals, reactive management; no strategy, and budget long-term plan No speed data; no meaningful Timely monitoring and crash data publication of relevant speed and crash data Episodic attention; occasional Long-term, multiyear, or enforcement crackdowns permanent perspective Haphazard or spot enforcement Technical implementation of Major portions of national or countermeasures state road network targeted Automated enforcement not Automated plus traditional authorized or rarely used enforcement Little attention to effectiveness of Penalties designed as part of the penalties integrated program Political and public support Active support and leadership of Politically invisible except when elected officials; management speed limits altered or held accountable for results automated enforcement proposed a Not necessarily all states. 

Case Studies of Safety Interventions 125 Effectiveness of Seat Belts and Belt Use Promotion Measures NHTSA has estimated that lap–shoulder belts are 45 percent effective in preventing fatal injury to front seat passenger car occupants in crashes and 60 percent effective for front seat light-truck occupants. That is, out of 100 hundred front seat car occupants not wearing belts who were killed in a crash, 45 would have been saved had they been wearing belts. Such estimates are derived by analysis of crashes of vehicles with two front seat occupants, one or both of whom were killed in the crash. For example, the chances of survival of two unbelted front seat occupants are about equal in a crash, but in crashes in which the driver is belted and the passenger is unbelted, the driver’s risk of death is less than half that of the passenger. The NHTSA estimate corrects for overreporting of belt use by crash survivors (Kahane 2000). Other countries have observed generally similar effectiveness (e.g., ONISR 2008, 158). Use of seat belts also mitigates nonfatal injuries; that is, in a crash in which an unbelted occupant probably would have suffered a severe injury, a belted occupant has an increased chance of escaping with a minor or moderate injury. NHTSA estimates indicate that each percentage point increase in belt use from the present level would prevent about 280 deaths annually (NHTSA 2008a, 207). Thus, according to this estimate, if belt use were increased from the 2009 level of 84 percent (for front seat passenger vehicle occupants) to 90 percent, U.S. fatalities would be reduced by 4.5 percent. In addition, the effectiveness of interventions to increase seat belt use is well established. Enactment of a primary seat belt law in place of a secondary law has been estimated to increase belt use by 14 percentage points on average and to reduce occupant fatalities by 8 percent (Hedlund et al. 2009, 2-11). A primary enforcement law is a state law authorizing police to stop a vehicle and issue a citation solely on the grounds of failure to use a seat belt. Secondary laws are laws that allow police to issue a citation for failure to use a belt only after the vehicle has been stopped for some other violation. In 2009, 26 states and the District of Columbia had primary enforcement seat belt laws (NHTSA 2009e). NHTSA has analyzed interstate differences in seat belt use rates to identify interventions and other factors correlated with high rates. Seat belt use rates vary greatly among the states. Rates for front seat occupants in 2008 were 95 percent or higher in five states (California, Hawaii, Michigan, Oregon, and Washington) and below 75 percent in nine states (Arkansas, Kentucky, Massachusetts, Mississippi, New Hampshire, Rhode Island, South Dakota, Wisconsin, and Wyoming) (NHTSA 2009d). The NHTSA analysis (Hedlund et al. 2008; NHTSA 2008c), based on 2005 use rates, found that existence of a primary seat belt use law and high enforcement effort (as measured by the rate of belt citations per capita issued in each state during the annual NHTSA-sponsored “Click It or Ticket” enforcement campaign) were correlated with high belt use rates. Among demographic and geographic differences examined, high population density was strongly correlated with high belt use. Other external factors analyzed in the study did not appear to be major determinants of the overall usage pattern, although the predominance of West Coast states among those with the highest rates suggests that some cultural factors may affect usage. Another NHTSA evaluation indicates that publicity campaigns linked to enforcement in the annual Click It or Ticket campaign increase belt use. Among the states participating in the 2002 campaign, the change in belt use increased consistently with increasing extent of state-paid advertising (Hedlund et al. 2009, 2-23). However, NHTSA’s analysis of factors correlated with higher state seat belt use rates found that states with low belt use tend to devote a larger fraction 

126 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations of their resources during Click It or Ticket campaigns to publicity, as opposed to police enforcement, than do states with high use rates (NHTSA 2008c). Significantly increasing seat belt use rates in the states that already have primary laws and serious enforcement will require increasing use among the population groups with consistently low rates historically. Such groups include men, younger drivers, rural drivers, pickup truck drivers, and possibly minorities (Hedlund et al. 2009, 2-24). High-visibility campaigns have been shown to increase use among these groups, but not necessarily to close the gap between these groups and the median. NHTSA has sponsored a series of demonstrations of techniques to reach the low-belt-use populations, which are conducted in conjunction with the annual Click It or Ticket campaign. The techniques tested included publicity and education activities targeted to particular geographic areas or demographic groups and adjustments to enforcement methods. Evaluations of these demonstrations report increases in belt use among the targeted populations after the campaign, but it is not clear whether the increases are greater than would have occurred through a standard state Click It or Ticket campaign without the supplemental targeted activities (Blomberg et al. 2008; Blomberg et al. 2009; Hedlund et al. 2009, 2-25). Trends in Seat Belt Use and Belt Laws By 2009, belt use had reached 84 percent for passenger vehicle front seat occupants in the United States, an increase of 16 percentage points since 1999. The rate was 88 percent in states with primary seat belt laws and 77 percent in other states. As seat belt use rates have increased in the United States, the percentage of persons killed in crashes who were not wearing a belt at the time of the crash has decreased (Figure 4-9). Belt use among persons killed in crashes is much lower than among all vehicle occupants. In 2007, 50 percent of all passenger vehicle occupants killed in crashes and 42 percent of front seat occupants killed were not wearing belts. In comparison, an average of 18 percent of front seat occupants of all vehicles on the road at any given time in 2007 were not wearing belts (NHTSA 2008a, 119; NHTSA 2008b; NHTSA 2009f). Federal law has required new cars sold in the United States to be equipped with seat belts since 1968 (Traffic Safety Center 2002). In 1984, New York became the first state to enact a law requiring vehicle occupants to use belts. Through 1989, 33 states and the District of Columbia had enacted seat belt laws, and by 1995 all states except New Hampshire had laws. Progress in enacting primary belt laws has been more gradual, but continuous. Thirty-one states and the District of Columbia had primary laws as of October 2010, an increase from 17 states with primary laws in 1999 (Figures 4-10 and 4-11). 

Case Studies of Safety Interventions 127 90 80 70 60 50 percent 40 30 20 10 0 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 front seat occupants of all passenger vehicles: % using restraints occupants killed in crashes: % not using restraints FIGURE 4-9 Percent wearing seat belts, all passenger vehicle front seat occupants; and percent not wearing seat belts, all passenger car and light truck occupants killed in crashes, United States, 1983–2009. (SOURCES: Hedlund et al. 2009, 2-1; NHTSA 2009c, Table 22; NHTSA 2009b.) 40 35 30 number of states 25 20 15 10 5 0 1984-89 1990-94 1995-99 2000-04 2005-09 States enacting initial belt law in period States enacting primary law in period FIGURE 4-10 Enactment of state seat belt laws, United States, 1984–2009. (SOURCE: IIHS 2009b.) Note: In 2010 through September, one new primary seat belt law (in Kansas) went into effect. 

128 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations FIGURE 4-11 State seat belt use laws as of October 2010. [SOURCE: Insurance Institute for Highway Safety (IIHS 2010); used with permission.] Comparisons with Benchmark Countries The laws of nearly every high-income country require use of seat belts (OECD and ECMT 2006, 25). The fraction of front seat occupants who use seat belts is lower in the United States than in Western Europe, Australia, or Canada but higher than in Japan (OECD and ECMT 2006, 25). Seat belt use rates by passenger vehicle occupants in some of the benchmark countries and in the United States in 2007 are compared in Table 4-4. Use of seat belts by rear seat occupants of passenger vehicles was required by law as of 2006 in all OECD countries except Japan, Korea, Georgia, Mexico, and the United States (OECD and International Transport Forum 2006, 25). Laws in 25 states and the District of Columbia require rear seat belt use (IIHS 2010). The U.S. rear seat belt use rate appears to be more comparable with those in other high-income countries than the front seat belt use rate. The history of seat belt use in the United States shows the consequence of decentralized safety regulation. Usage grew during the 1980s and early 1990s until all states had seat belt laws. The use rate has continued to grow, but more slowly, in the past 15 years as the number of states with primary laws has increased (Figure 4-12). In the United Kingdom, a national law requiring front seat occupant seat belt use went into effect in 1983, and belt use immediately jumped from 37 to 95 percent. A slight decline occurred after the initial spike, but rates have returned to the 95 percent level (Figure 4-12). Seat belt use by adult rear seat occupants was required in 1991. 

Case Studies of Safety Interventions 129 TABLE 4-4 Seat Belt Use Rates in Passenger Vehicles, 2007 Drivers Adult Front Seat Rear Seat Occupants, Expressways Occupants All Roads Autoroutes Urban Areas Germany 98 93 France 99 98 98 83 Netherlands 93 Swedena 94 74 Great Britain 92 94 69 United States 84b 89b 82 76 NOTE: Rates are percentages. a Rates are for 2006. b Drivers and front seat passengers. SOURCES: ONISR 2009a; ONISR 2008, 157; Breen et al. 2007, 55; DfT 2007; NHTSA 2008b; NHTSA 2009f. France approached belt use laws more gradually: a front seat occupant seat belt law was enacted in 1973, applicable only on rural roads and in vehicles first registered in 1970 or later. A 1975 law required belts on urban expressways and all urban roads at night, and a 1979 law required belt use by front occupants on all urban roads at all times. In 1989, belt use in light trucks was required, and in 1990 rear seat belt use was required in vehicles so equipped. In 1994, a point penalty toward license suspension for failure to wear a belt was introduced (ONISR 2008, 247–250). The 1979 urban use law brought belt use above 50 percent, and usage has increased nearly continuously since that time (Figure 4-12). The high-intensity nationwide Seat belt use rates, passenger vehicle front occupants--U.S., Great Britain, and France 1982-2009 100 90 80 70 60 percent 50 40 30 20 10 0 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 United States Great Britain France FIGURE 4-12 Seat belt use rates, passenger vehicle front occupants, United States, Great Britain, and France, 1982–2009. (SOURCES: Hedlund et al. 2009, 2-1; NHTSA 2009e; ONISR 2008, 157; DfT 2007.) 

130 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations traffic safety enforcement and publicity campaign initiated in 2002 (described in Chapter 3) probably helped raise seat belt use above the 90 percent level. Differences in historical belt use rates among the United States, the United Kingdom, and France do not appear to be part of the explanation of slower improvement in safety in the United States in recent decades. The substantial absolute increase in the seat belt use rate probably explains a large share of U.S. safety progress over the past 20 years. In the United Kingdom and France, increasing belt use probably has accounted for a smaller share of total improvement in the period because use rates were initially higher than in the United States. The effort devoted to seat belt law enforcement in the United Kingdom and France today is light in terms of frequency of citations. The low frequency of citations is consistent with the high belt usage rates in these countries; that is, violations of the law are uncommon. Citations for failure to wear seat belts in 2007 in France were 3 percent of all moving violations, and the rate of citations was 10 per 1,000 registered drivers (Table 3-1); in Great Britain in 2006, they were 5 percent of all moving violations and the rate of citations was 7 per 1,000 drivers (Table 3- 2). The seat belt citation rate in Sweden in 2006 was 9 per 1,000 drivers (Breen et al. 2007, 32, 55). For comparison, in New York State in 2007, citations for failure to wear seat belts were 11 percent of all traffic safety law violations ticketed, and the rate of citations was 41 per 1,000 drivers (New York State Governor’s Traffic Safety Committee 2008, 22). New York’s seat belt use rate in 2007 was 83.5 percent, slightly above the national average. Some of the benchmark countries are giving increased attention to increasing belt use by rear seat occupants and commercial vehicle occupants. Summary Observations The cases of seat belts and of motorcycle helmets (discussed in the next section) provide clear illustrations of how public and political attitudes can restrain risk-reducing measures despite the availability of effective and well-managed countermeasure programs in many states. The effectiveness of seat belts in reducing casualties and of specific interventions (primary laws and high-visibility enforcement) in increasing usage are well established by research and by the experience of many states. The interventions are not complex or expensive compared with the efforts required for speed control or impaired-driving control. Nonetheless, some jurisdictions have chosen not to apply these measures. The benchmark countries have attained higher rates of seat belt usage than the United States through uniform national imposition and enforcement of seat belt laws. Consequently, increasing belt use is not as high a priority for most of these countries as it is in the United States. MOTORCYCLE HELMET LAWS This section follows the same general outline as the preceding section on speed control: the first subsection below describes the effectiveness of helmet laws in reducing injury risk; the second presents trends in motorcycle fatalities, helmet use, and helmet regulations; the third contains international comparisons; the fourth presents some illustrative histories of changes in federal and state helmet laws; and the final subsection contains conclusions. 

Case Studies of Safety Interventions 131 Effects of Helmet Use and Helmet Laws on Injury Risk NHTSA estimates that motorcycle helmets are 37 percent effective in preventing motorcycle occupant fatalities; that is, of the 2,146 unhelmeted motorcycle occupants killed in crashes in 2008, 37 percent, or 794, would have survived if they had been wearing helmets. NHTSA derived the estimate from an analysis of fatal crashes of motorcycles with two occupants during 1993–2002. For example, in crashes where neither the rider (i.e., the driver) nor the passenger was helmeted and in crashes where both were helmeted, the passenger was about 10 percent less likely to be killed than the rider. However, in crashes where the passenger wore a helmet and the rider did not, the passenger was 60 percent less likely than the rider to be killed (NHTSA 2004; NHTSA 2007c). Other data support NHTSA’s conclusion about the effectiveness of motorcycle helmets. An analysis of injuries to motorcycle occupants in crashes found that unhelmeted occupants were three times more likely to suffer brain injuries than helmeted occupants (NHTSA 2005b). Studies of the effects of repeal of helmet laws in Colorado, Kentucky, and Louisiana showed changes in fatality frequency correlating with changes in helmet use after repeal (NHTSA 2004, 4). Some published studies have reported contrary findings, but the preponderance of research indicates that wearing a helmet reduces the risk of injury and death (Neiman 2007, 14–17). Opponents of helmet laws have argued that helmets restrict sight and hearing and therefore may increase the risk of a crash, offsetting the benefit of lower injury risk in the event of a crash. NHTSA has sponsored a test-track study that concluded that effects of helmets on hearing and sight are inconsequential (McKnight and McKnight 1994). Helmet laws have been shown to be highly effective in ensuring helmet use, in large part because a violation of the law is always evident. A 1991 General Accounting Office review summarized nine studies that reported compliance rates of 92 to 100 percent with universal helmet laws (i.e., laws requiring all motorcycle occupants to wear a helmet), helmet use rates of 42 to 59 percent in states with no law or a law with limited applicability, and low compliance with state laws requiring use by minors only (GAO 1991, 4). A June 2009 NHTSA roadside survey found that the rate of use of helmets complying with federal standards was 86 percent in states with universal helmet laws and 55 percent in other states (NHTSA 2009a). NHTSA studies have also reported that repeal of a helmet law in a state leads to a reduction in use and that enactment of a law increases use (NHTSA 1998; Ulmer and Preusser 2003). Trends: Motorcycle Crashes, Helmet Regulation, and Helmet Use Helmet Regulation and Helmet Use Annual motorcycle occupant fatalities increased by 138 percent from 2,227 in 1995 to 5,290 in 2008. Motorcycle occupant fatalities rose from 5 percent of all U.S. traffic fatalities in 1995 to 14 percent in 2008. The occupant fatality rate per registered motorcycle increased 23 percent, and the rate per mile of motorcycle travel increased 67 percent in this period (Figure 4-13) (NHTSA 2009c, 18, 28; NHTSA 2010). Annual motorcycle occupant fatalities declined 16 percent in 2009, to 4,462, the first annual decline in 12 years. The decline may have been a consequence of the economic recession. (Part of the discrepancy between the increases in the two rates may be the result of problems in measuring motorcycle mileage.) The motorcycle occupant fatality rate per vehicle mile was 34 times greater than the rate for passenger car 

132 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations occupants in 2004 (NHTSA 2007c). The causes for the rapid rise in motorcycle fatality rates are not understood, although NHTSA reports that the market share of motorcycles with larger engine sizes has increased. Helmet use among fatally injured motorcycle occupants has remained constant in the past decade (Shankar and Varghese 2006). In 2010, 20 states had laws requiring all motorcycle occupants to use helmets, a decline from a peak of 47 states with such laws in 1975 (Figure 4-14). Fifty-six percent of all motorcycle registrations in 2000 were in states without a universal helmet use law (Ulmer and Preusser 2003). Most states have laws requiring minors to wear helmets, and a few require helmets only for minors and newly licensed riders. A few states have required riders not wearing helmets to have medical insurance (Ulmer and Preusser 2003; Hedlund et al. 2007). NHTSA’s periodic roadside helmet use surveys found the following trend in use (Glassenbrenner and Ye 2006; NHTSA 2009a): Survey Date Percentage of Occupants with Helmets October 1994 63 October 1996 64 October 1998 67 October 2000 71 June 2002 58 June 2004 58 June 2005 48 June 2006 51 June 2007 58 June 2008 63 June 2009 67 The apparent trend in the annual survey results probably is affected by a seasonal difference between use rates in June and October. Therefore, the actual long-term trend is not clear, although helmet use rates rose consistently from 2005 through 2009. Comparisons with Benchmark Nations By some measures, motorcycle crashes appear as an even more serious health problem in Europe than in the United States. In 14 European Union countries in 2004, 5,500 motorcycle and moped riders and passengers were killed. This was 20 percent of all road accident fatalities, twice the U.S. motorcycle share of fatalities. Annual motorcycle and moped fatalities declined by 6 percent in the decade 1995–2004 (ERSO 2007). Motorcycle and moped fatality rates per registered vehicle are similar in the United States (65 fatalities per 100,000 vehicles in 2002, 68 in 2008), in France (60 in 2002), and in the United Kingdom (59 in 2002), but they are reportedly much lower in Italy (14 in 1998) and in Spain (19 in 2002) (SafetyNet 2005). The source of the divergence of rates among European countries is not evident but may relate to differences in the mix of motorcycles and mopeds. IIHS reports that laws requiring motorcyclists to wear helmets are in effect in nearly every European country, Canada, Australia, New Zealand, and Japan (IIHS 2007), although the scope of laws in these countries is not reported and compliance in some regions may be relatively low. 

Case Studies of Safety Interventions 133 At least one European country has acted recently to strengthen its helmet rules. In Italy, a 2000 law required helmet use for all motorcycle, motorbike, and moped occupants. The previous law, in effect since 1986, required helmets for all motorcycle riders but only for moped riders under age 18. Italy has twice as many mopeds in use as motorcycles. An evaluation of the impact of the law after 1 year reported high rates of compliance and a 66 percent reduction in hospital admissions for traumatic head injuries to motorcycle and moped occupants in one region of Italy (Servadei et al. 2003). European countries recognize the need for additional motorcycle safety initiatives, including infrastructure design and vehicle design measures. Research has identified hazards in rural road conditions that are particularly significant for motorcycles (ACEM 2009b). Also, the European Union has considered adoption of a standard for advanced braking systems for motorcycles (ACEM 2009a). The European motorcycle manufacturing industry sponsors a safety research and promotion program (ACEM 2006). The industry organization has begun promoting the use of protective clothing and asserts that data from a motorcycle crash investigation study sponsored jointly by industry and government demonstrate the effectiveness of protective clothing (e.g., specially designed boots, gloves, and jackets) in reducing the severity of motorcycle crash injuries (ACEM 2010). Examples of Changes in Helmet Laws Federal Helmet Use Laws Enactment and repeal of state helmet laws has been largely a consequence of changes in federal highway safety program requirements. Two safety acts enacted in 1966 created the predecessor organizations to NHTSA and authorized the Secretary of Transportation to issue Highway Safety Program Standards. States would be required to comply with the standards or lose a portion of federal-aid highway funds. The first standards, issued in 1967, included a requirement for a universal helmet use law. By 1975, 47 states had enacted such a law. In 1975, for the first time, three states (California, Illinois, and Utah) were threatened with penalties for failure to enact helmet laws, but Congress intervened by repealing the penalties. By 1980 the number of states with universal helmet laws had fallen to 20. A few additional states enacted laws in the early 1990s. In 1992, Congress reinstated milder penalties for states without universal helmet laws (part of the federal-aid highway funds for states without helmet laws were to be transferred to the states’ highway safety programs) and provided incentive grants rewarding states that enacted and enforced both helmet laws and safety belt laws. This program appears to have had little effect on state legislation. Congress eliminated the new penalties in 1995 (Ulmer and Preusser 2003; Hedlund 2007; LaHeist 1998; Hedlund et al. 2007). Nearly all the state universal helmet laws in effect today were originally enacted to comply with the federal requirement. 

134 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Annual motorcycle occupant fatalities, 1995-2009 6,000 5,000 4,000 fatalities 3,000 2,000 1,000 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 year Motorcycle occupant fatality rates, 1995-2008 80 70 60 50 fatality rate 40 30 20 10 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 year per 100,000 vehicles per 100 million VMT FIGURE 4-13 Annual motorcycle occupant fatalities, 1995–2009 (top) and motorcycle occupant fatality rates, United States, 1995–2008 (bottom). (SOURCES: NHTSA 2009c, 18, 28; NHTSA 2010.) 

Case Studies of Safety Interventions 135 FIGURE 4-14 Number of states with universal motorcycle helmet use laws, 1966–2003. (SOURCE: Ulmer and Northrup 2005.) [Since 2003, one state (Louisiana in 2004) has enacted a universal helmet law.] The history of federal helmet laws is similar in some respects to that of the NMSL. The federal government forcefully intervened in a regulatory matter that had formerly been exclusively determined by the states; state practices initially were greatly changed, but a reaction, in part on philosophical states-rights grounds, led to a rollback of federal involvement. The 1995 National Highway System Designation Act eliminated the federal penalty for states without helmet laws as well as the NMSL. Both provisions were part of a package of program reforms aimed at reducing federal control over state highway programs. State Helmet Laws Most of the repeals of state helmet laws occurred in the 1970s (Figure 4-14) after the elimination of federal sanctions. However, several states have changed their laws more recently. Since 1990, Arkansas (1997), Florida (2000), Kentucky (1998), Louisiana (1999), Pennsylvania (2003), and Texas (1997) have repealed universal helmet use requirements, and California (1992), Connecticut (1990), Louisiana (2004), Maryland (1992), and Washington (1990) have enacted such requirements. Louisiana has enacted a universal helmet use law three times: in 1968 (repealed in 1976), 1982 (repealed in 1999), and 2004. Texas enacted a law in 1967, repealed it in 1977, reinstated it in 1989, and repealed it again in 1997 (NHTSA 2007b, 184– 185). NHTSA has published evaluations of the recent helmet law repeals in Florida, Kentucky, Louisiana, Arkansas, and Texas (Ulmer and Northrup 2005; Ulmer and Preusser 2003; Preusser 

136 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations et al. 2000). The evaluations compare motorcycle injury and fatality trends in the subject states with national trends before and after the state law changes. For example, in Kentucky (repeal in 1998), motorcycle occupant fatalities per registered motorcycle increased 39 percent from 1996– 1997 to 1999–2000, compared with 14 percent for the entire United States; in Louisiana (repeal in 1999), fatalities per registered motorcycle increased 74 percent from 1997–1998 to 2000, compared with 16 percent in the United States. Injury rates increased in both states and declined in the United States. The NHTSA state studies do not describe the political debate that led to the changes in state laws, but NHTSA has summarized the common arguments of opponents of motorcycle helmet laws in these debates (NHTSA 1998): • Helmet laws violate individual rights: because motorcycle riders suffer the primary consequences of crashes, they should have the right to decide whether the benefits of helmets outweigh their disadvantages. • Helmets cause neck injuries and impair hearing and sight, increasing the likelihood of crashes. • Statistical studies do not definitively show safety benefits from helmet laws because they do not properly take into account nonfatal crashes or changes in motorcycle ownership and use. • Laws requiring only minors or new riders to wear helmets are effective and sufficient. NHTSA-conducted surveys have concluded that 80 percent of U.S. adults and 50 percent of adult motorcycle riders support helmet use laws (NHTSA 2005b). A 2004 Wall Street Journal article described motorcyclist organizing and lobbying efforts leading to repeal of the Pennsylvania universal helmet use law in 2003. The state chapter of the bikers’ organization Alliance of Bikers Aimed Toward Education (ABATE) organized an effective grassroots campaign that included hiring a full-time lobbyist to promote legislation and organizing constituent visits to legislators. ABATE established a relationship with the governor through participation in a hospital charity and gained his endorsement. Legislators reported receiving contacts from numerous bikers in the weeks before the vote and from few opponents of repeal (Lundegaard 2004). In Pennsylvania and other states, ABATE chapters have set up political action committees, BikePACs, to contribute to election campaigns of politicians supporting their legislative agenda. ABATE chapters endorse political candidates and publish voters’ guides and legislative issues guides. Motorcyclist political organizations have been active in some states since the early 1970s, when they were formed in response to the first federal motorcycle and helmet regulations (ABATE of California n.d.; Jones and Bayer 2007). In Louisiana, the governor, a motorcyclist, led the legislative initiative that resulted in repeal of the state’s helmet law in 1999. The succeeding governor actively supported reinstatement of the law in 2004. Evidence of increased motorcycle fatalities after repeal and of the cost to the state for medical care was reported to have influenced legislators’ votes on reinstating the helmet requirement (Stone 2004). Concluding Observations • Well-organized grassroots advocacy on legislative issues is effective in the United States, especially for issues that most affect a well-defined group and do not attract strong 

Case Studies of Safety Interventions 137 interest in the general population. On an issue like motorcycle helmets, the lobbying of mainstream safety groups may inevitably be less politically effective than that of the single-issue groups opposing them. The importance of advocacy groups may be a significant difference between the United States and many other countries in the forming of safety policy. • Motorcycle helmet laws are a more purely legislative issue than most other forms of safety interventions; that is, historically, enacting laws has been sufficient to produce results. In contrast, in other areas of highway safety, such as speed control and hazard elimination, effective execution of programs poses great management challenges and is at least as critical for success as the legal framework. • The history of federal motorcycle helmet regulation is similar to that of the federal speed limit laws. In both cases, the penalty of loss of federal highway construction funds was used to induce conformity of state laws to federal standards. Both lost support and were repealed on account of the states’ interest in limiting federal control over their transportation programs. • High-level political leadership in the legislature or by the governor was essential in enactment of the only recent universal helmet use law (Louisiana) and in opposing initiatives to overturn laws in other states (e.g., in the case of the Michigan governor’s veto of a 2006 repeal bill). • Information about the safety consequences and costs to the state of helmet law repeal has influenced legislators when it has been presented in a timely and forceful manner. Coordinated, proactive information campaigns from the executive agencies when repeal bills have been introduced have discouraged repeals in some states. • Motorcycle safety programs employing training, education, licensing, and enforcement are conducted in states with no universal helmet use law. Such activities receive the support of motorcyclists. Research has failed to demonstrate that rider training can reduce motorcycle crashes (IIHS 2007), although training programs are endorsed by NHTSA as one component of its Motorcycle Safety Program (NHTSA 2003). NHTSA’s Countermeasures That Work (Hedlund et al. 2009, 5-4–5-22) describes three categories of interventions to prevent motorcycle casualties in addition to helmets: measures targeting alcohol-impaired motorcycle use, operator licensing and training, and communications to promote use of protective and conspicuous clothing and motorist awareness of motorcyclists. According to the review, evaluations of motorcyclist training have found only minimal effectiveness and no evaluations of the other interventions have been carried out, although some of them are commonly used and the authors view some as potentially effective (e.g., alcohol enforcement targeting cyclists and improvements in conspicuity). Motorcycle operation by persons without the required license or endorsement is common and may be an underemphasized risk factor. Emphasis on these kinds of safety efforts would be consistent with the recommendation of the FHWA report Halving Roadway Fatalities that the necessary elements of a successful program are identifying the greatest safety problems, selecting interventions that are demonstrated to be effective, and then systemically implementing those that can gain political and public support (Johnston 2006, 16). HIGHWAY NETWORK SCREENING AND SAFE ROAD DESIGN In contrast to speed management and motorcycle helmet laws, which seek to reduce high-risk driver behavior, highway network screening aims to make the infrastructure inherently safer for the average driver. Every U.S. state highway agency has a program to identify locations on the 

138 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations road system with a relatively high frequency of crashes and to apply treatments to reduce the excess risk at these locations. Such a program requires a data system that records the location and characteristics of each crash and the characteristics of each road segment on the system, an analysis method for identifying and prioritizing the high-hazard locations, and a repertoire of treatments that can be used in designing a correction for each of the highest-priority locations. Treatments may include alignment adjustments, widening of shoulders, removal of roadside obstacles, improvement of signing and pavement markings, intersection improvements, installation of barriers, and increases in traffic law enforcement (although these programs traditionally emphasize minor capital and traffic control improvements and may not always coordinate with enforcement agencies). For new roads and projects to reconstruct or rehabilitate roads, design standards promulgated by FHWA (applicable to projects funded with federal aid) and design guides published by AASHTO offer rules with regard to alignment, cross section [lane, shoulder, and median widths and superelevation (banking) on curves], the roadside environment, and other features intended to provide an acceptable level of safety. The AASHTO Highway Safety Manual and its supporting design tools (See Box 3-7 in Chapter 3) are expected to provide a sounder basis than traditional design standards for assessing the safety of designs for new roads and road improvements. The first section below discusses the relationship of roadway characteristics to safety. The second describes U.S. hazard elimination practices, and the third describes related activities in other countries. The final section presents summary observations. Relationship of Road Characteristics to Crash and Injury Risk A 1987 TRB committee, in a study that recommended design practices for highway resurfacing, restoration, and rehabilitation (RRR) projects, explained the relationship between highway characteristics and crash risk as follows (TRB 1987, 78): Highway features affect safety by: • Influencing the ability of the driver to maintain vehicle control and identify hazards. Significant features include lane width, alignment, sight distance, superelevation (i.e., banking on curves), and pavement surface characteristics; • Influencing the number and types of opportunities that exist for conflicts between vehicles. Significant features include access control, intersection design, number of lanes, and medians; • Affecting the consequences of an out-of-control vehicle leaving the travel lanes. Significant features include shoulder width and type, edge drop, roadside conditions, side slopes, and guardrail; and • Affecting the behavior and attentiveness of the driver, particularly, the choice of travel speed. Driver behavior is affected by virtually all elements of the roadway environment. Driver behavior is affected by lane width and alignment, the appearance to the driver of the roadside environment, the design of signs and markings intended to inform the driver, and many other design features of the roadway environment (Smiley 2008). A connection between safety and road characteristics is evident in data on fatality rates per mile of travel for different road classes. On rural Interstates in 2007, the rate was 0.6 

Case Studies of Safety Interventions 139 fatalities per 100 million vehicle kilometers of travel; on other rural arterials, 1.4; and on rural minor roads (collector and local road classes), 1.8, three times higher than the rural Interstate rate and five times higher than the urban Interstate rate (FHWA n.d. a) (see Figure 2-13 in Chapter 2). The design of Interstates eliminates or greatly reduces the risk of head-on collisions, collisions with fixed objects, and intersection crashes (Evans 2004, 102–105). In urban areas the difference is less (0.6 fatalities per 100 million vehicle miles on Interstates, 1.1 on urban local and collector roads), presumably in part because many local urban roads are low speed. Crash circumstances also indicate the connection between safety and road design. For example, NHTSA reports that 22 percent of all fatal crashes in 2008 occurred at intersections or were intersection-related and that 42 percent of all fatal crashes were single-vehicle run-off-road crashes (NHTSA 2010, 51–52). The TRB RRR committee observed that despite decades of research to measure the effects of road design features on safety, highway agencies still had limited ability to predict the safety benefits resulting from a roadway improvement (TRB 1987, 78). This conclusion still appears valid. Measurement is difficult because of the multiple factors that affect crash risk; because of chronic deficiencies in data; and because some critical factors, including vehicle characteristics and driving habits, change over time. To design and prioritize projects to treat high-hazard locations, states use the best available information to develop tables of crash reduction factors, which are estimates of the likely safety gain from individual road improvements. For example, research commissioned by the TRB RRR committee estimated that on a two-lane rural road with a 5-foot-wide roadside clear zone, widening the clear zone to 20 feet would reduce the number of single-vehicle, head-on, and sideswipe crashes by 35 percent on average (TRB 1987, 85–86). FHWA has estimated that the cumulative impact of the Hazard Elimination Program and the grade crossing program was to prevent 58,000 deaths and 1.1 million nonfatal injuries between 1974 and 1995. FHWA has also estimated that each $100 million spent in targeted highway safety capital improvements results in 14.5 fewer fatalities per year (FHWA 1996). A more recent analysis found a nationwide benefit–cost ratio of 11 for all Hazard Elimination Program projects and 8 for highway–rail grade crossing projects conducted from 1995 to 2000 (Li et al. 2004). To the extent that these estimates were based on the states’ projections of project benefits rather than on evaluations after projects were completed, their reliability is unknown. It would be useful to know whether any states have retrospectively evaluated the results of their improvements at high-hazard locations to determine the extent to which expected crash reductions were attained. In contrast to these estimates, the studies described in Chapter 2 that have used statistical methods to explain differences in crash rates among the states or among countries have not found a strong correlation between safety and infrastructure spending or condition. For example, the study of effects of road investment and other factors on U.S. state road casualty frequency concluded that “changes in highway infrastructure that occurred between 1984 and 1997 have not reduced traffic fatalities and injuries and have even had the effect of increasing total fatalities and injuries. . . . [T]he fact that adding new and higher design standard lane miles leads to increased fatalities and injuries suggests that new ‘improved’ design standards are not achieving safety benefits” (Noland 2003, 610). As explained in Chapter 2, the author’s interpretation of the statistical results is problematic because the study excludes vehicle miles of travel as an explanatory variable. In addition, because this study used data on overall upgrading of highway system standards and not on spot improvement projects, its results are not directly relevant to 

140 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations highway network screening programs. Nonetheless, its results challenge standard assumptions in highway design. A research program sponsored by the U.S. Department of Transportation and by the states through AASHTO has increased understanding of the safety effects of highway design and traffic control features and has developed new knowledge and organized existing knowledge into tools for application in project development (see Box 3-7 in Chapter 3). The Highway Safety Manual published by AASHTO in 2010 is a first step in providing a methodology that quantifies the expected safety effects of proposed highway improvement projects and allows highway designers to compare the expected safety performance of design alternatives. Software tools to implement the Highway Safety Manual procedures include the SafetyAnalyst and the Interactive Highway Safety Design Model. To achieve safety improvement, the Highway Safety Manual procedures and the available software tools will need to be institutionalized in the safety management process and the project development process. U.S. Practices The two subsections below describe a representative state highway network screening program and the main federal grant program for state and local highway hazard elimination projects. Funding for hazard elimination in most states is mainly from grants from the federal-aid highway program specifically provided for the purpose [formerly the Hazard Elimination and Highway– Rail Grade Crossings Programs, now the Highway Safety Improvement Program (HSIP) defined in the 2005 federal surface transportation act (SAFETEA-LU)]. Projects eligible for federal funding assistance are defined as follows [23 U.S.C. Section 148(a)]: In general.—The term “highway safety improvement project” means a project described in the State strategic highway safety plan that (i) corrects or improves a hazardous road location or feature; or (ii) addresses a highway safety problem. The act also lists categories of eligible projects. The state strategic highway safety plans that the act requires are described in Chapter 3. Example of a State Highway Network Screening Program The following outline of Oregon’s Highway Safety Program (ODOT 2007) is presented to illustrate the procedures in a representative state program to identify and correct high-hazard locations. The Oregon Department of Transportation (ODOT) currently spends approximately $28 million annually on its Highway Safety Program. Funding includes $14 million from the federal HSIP and an equal amount from state funds and other federal funds. The state probably is unusual in doubling its federal HSIP grant; the minimum required state matching share is 10 percent. For comparison, the ODOT highway budget is approximately $1 billion annually. The Highway Safety Program funds mainly small infrastructure improvement projects at high-hazard locations. For example, eligible improvements include alignment adjustments, signal installation, guardrails, barriers, illumination, pavement markings, signs, roadside fixed- object removal, and traffic calming features. With a few exceptions, noninfrastructure 

Case Studies of Safety Interventions 141 treatments such as increased enforcement are funded through other programs. Projects may be on any public road in the state owned by state or local government. Each of ODOT’s five regions receives a funding allocation, and projects are developed and nominated by the regions. The department conducts statewide analyses to identify high- hazard locations. The Safety Priority Index System (SPIS) evaluates the state highway system in 0.1-mile segments to identify problem locations on the basis of crash frequency, severity, and rate. Each region is given a list of the sites in its territory to which the SPIS has assigned a priority in the top 5 percent of all sites statewide. The regions then evaluate these sites for possible corrective action. A separate analysis [the Safety Investment Program (SIP)] ranks 5- mile segments of the state highway system according to the frequency of fatal and serious injury crashes in a 3-year period. Local governments may also nominate projects to their regional office for inclusion in the Highway Safety Program. Each region assembles a package of project requests, limited by its funding allocation and prioritized according to criteria specified by ODOT (including SPIS ranking, SIP ranking, and benefit–cost ratio). The Oregon Transportation Commission makes the final decision on which safety projects are included in the Statewide Transportation Improvement Program. A noteworthy component of Oregon safety activities is the state’s safety corridor program, which constitutes a more comprehensive and systematic approach to reducing the risk of travel on a particular road than the traditional, infrastructure-oriented hazard elimination program. The state publishes an annual Safety Corridor Plan that identifies corridors on state highways that have been given high priority for crash reduction. The plan also reports on progress in meeting crash reduction objectives in each corridor. Corridor treatments are designed that combine enforcement, education (including publicity campaigns and school programs), engineering (traffic control devices and capital improvements to the roads in the corridor), and emergency medical services (EMS) improvements. Coordination is required with local governments on enforcement and EMS and with the state’s capital programming process where capital improvements are called for. Other states also conduct corridor safety programs. For example, the California program, which has treated 123 corridors since 1993, depends on cooperation of the highway patrol, the state highway agency, local police, and local EMS. Federal HSIP The federal HSIP established in SAFETEA-LU (Section 1401) is the current version of a grant program that has been in operation since at least 1975. The law authorizes $1.2 billion annually for 2006–2009 for projects to correct high-hazard locations on any public road. Funds are allocated by formula to the states. Within the program, the law sets aside $220 million annually for rail–highway grade crossing projects and $90 million annually for improvements on high-risk rural roads. A new provision requires each state to coordinate its hazard elimination program with the state’s federally required Strategic Highway Safety Plan. The intent of the strategic plan is to identify critical highway safety problems and opportunities. The plan must be based on accurate and timely safety data; be developed in consultation with local governments and private stakeholders; specify performance-based goals; and incorporate strategies involving infrastructure improvement, driver behavior regulation, education, and emergency services. State data systems supporting the plan must be capable of identifying high-hazard locations and 

142 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations evaluating countermeasures. The state’s HSIP is to be developed within the framework of the strategic plan, presumably to ensure that interested parties are consulted in forming the program and that the full range of countermeasures is considered (FHWA 2005). Practices in the Benchmark Countries The four benchmark country safety programs described in Chapter 4, and probably the programs of all the high-income countries, include a traditional hazard elimination component. In addition, all countries have design standards for new construction and reconstruction that are intended to provide for safety. However, a shift in design emphasis appears to be emerging in some of the benchmark countries’ road programs that departs from conventional practice in three ways. First, designs are based on a new and more firmly researched-based understanding of the relationship of design to crash and casualty risk (for example, an appreciation of the influence of geometric design on driver behavior, especially selection of speed). Second, risk reduction is given higher priority and earlier attention in the design of projects and in project programming. Finally, designs show a willingness to trade a degree of traveler convenience for the sake of safety. The new approach entails greater road agency accountability for the safety consequences of road designs—the designer is expected to quantify the expected crash frequency on the new or improved road and to justify the design level of risk as acceptable. Activities such as the road safety audit and the road assessment programs described below reinforce accountability. This design philosophy is an ideal articulated in national safety plans that has yet to be fully realized in practice; nonetheless, it is influencing practice in some countries. Several of the benchmark countries highlight road design as central to their long-term safety strategies. Examples are the following: • In Sweden, the Vision Zero policy described in Chapter 3 emphasizes road design. Roads are to be built or reconstructed with features that ensure low casualty risk, and risk reduction opportunity is a factor in project selection. Safety design features include roundabouts replacing intersections, barriers separating opposing lanes, and the 2+1 lane design. • In Australia, the most recent Australian Transport Council Action Plan, described in Chapter 3, endorses a “safe system” framework, which has been adopted in several of the Australian state safety plans. The framework embodies a systems perspective, that is, a design philosophy that seeks to optimize the performance of the road system as a whole, with consideration of the characteristics of vehicles, roads, and users. The safety plans acknowledge that, now that Australia has made large safety improvements through intensified enforcement, greater focus on safe infrastructure design will be necessary to sustain improvement in the future. • In the Netherlands, the strategy of the “sustainable safety” policy has similarities with the Swedish Vision Zero strategy. It adopts the systems perspective and emphasizes road design as a means of regulating driver behavior. The road system is classified by function, and design features identified as appropriate to each function are being introduced, for example, traffic calming features in built-up areas and alignment and lane width adjustments on two-lane roads that signal appropriate speeds to drivers. This design technique is referred to as the self- explaining road (Kraay 2002, 2–3, 6–7). Because these strategies involve road reconstruction, they can only be brought to fruition gradually over time. In addition, fully implementing them will require the analytical ability to 

Case Studies of Safety Interventions 143 design a road to meet a quantitative crash risk standard (i.e., a specified expected crash risk on a road, given stated assumptions about traffic characteristics). This ability is not yet fully in place in the United States or other countries, although, as described above, some of the necessary analytical tools have been under development in the United States. Road Assessment Programs A new evaluation practice, the Road Assessment Program (RAP), in operation in Europe and Australia and under development in the United States, is bringing greater attention to the problem of upgrading the inherent safety of road infrastructure. RAPs assemble and publicize crash data and other safety information for individual road segments. The programs publish maps that indicate the relative safety of each of the roads in a jurisdiction. Leadership in creating and managing the programs has come from the national automobile clubs in those countries, in cooperation with governmental agencies. In the United States, the AAA Foundation is organizing pilot implementations of usRAP in cooperation with eight states (Iowa, Michigan, Florida, New Jersey, Illinois, Kentucky, New Mexico, and Utah) (usRAP 2008; Harwood et al. 2010). The creation of RAP was inspired by the success of the European New Car Assessment Program (NCAP), which was organized in the mid-1990s as a joint effort of automobile clubs, governments, and the European Commission to conduct new-car crash tests and publish the results as consumer information. The NCAP is believed to have influenced vehicle designs strongly as manufacturers competitively seek higher ratings for their new models. In Europe, the RAP maps attract considerable public attention, which exerts pressure on road agencies to act on the high-crash locations. RAP is a potentially significant experiment in highway safety action. A nongovernmental initiative, it aims to increase public demand for safety and to make public officials more accountable for safety performance of highways by revealing and publicizing hazards. The road protection scores and star ratings produced by the RAP assessments (Harwood et al. 2010, 113–150) are useful as intermediate output measures of state hazard elimination programs. Road Safety Audits A second evaluation practice in use in the benchmark nations and in some U.S. states, road safety audits, is increasing awareness of the potential for reducing casualty risk through changes in road design and is reinforcing public accountability of road agency managers. A road safety audit is a formal, independent examination of the safety of the design of a road construction or reconstruction project. A similar procedure, called a road safety audit review in the United States, has been developed for roads already in use. Road safety audits originated in the United Kingdom, where they have been compulsory since 1991 for major projects, and are practiced in Canada, Australia, New Zealand, Germany, and some U.S. states (Wilson and Lipinski 2004, 1– 4, 21–25; ETSC 2005). FHWA identifies critical differences between a road safety audit and conventional methods of checking the safety of a road design (FHWA n.d. b). The audit • Is performed by a team independent of the project; 

144 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations • Is performed by a multidisciplinary team (for example, expertise of team members may include traffic engineering, road design, traffic enforcement, roadway maintenance, and crash investigation); • Considers interactions of motor vehicles, bicycles, and pedestrians; • Considers especially human factors issues in the design, that is, the demands the road environment places on the driver’s attention, reactions, and judgment; • Generates a formal audit report; and • Requires a formal response to the audit from the parties responsible for the audit. The requirements for independence of the audit and for a formal report and response reinforce accountability of the agency conducting the project. The interdisciplinary approach ensures that features affecting risk that road designers have not been technically prepared to recognize in the past are not overlooked. Summary Observations Although hazard elimination programs are prominent in the safety strategies of most state transportation programs, the overall performance of these programs is difficult to assess. A systematic comparative evaluation to determine how much the programs contribute to safety improvement and to identify the attributes of the most effective programs would be worthwhile. In-depth examinations of hazard elimination programs in a sample of states (possibly supplemented with international comparisons) would seek to answer the following questions: • Do the state hazard elimination programs produce appreciable reductions in crashes at reasonable cost? Especially, are there state programs that are much more effective than the average, or practices in other countries that are more effective than U.S. programs? Overall evaluations of the effectiveness of these programs have been rare and have used imperfect methodologies. • Do states successfully manage the interagency coordination that an effective hazard elimination program requires? The parties that may be involved include several offices within the highway agency (which administers the federal HSIP funds), the state agency responsible for administering NHTSA highway safety grants (which may fund enforcement, data systems, public information programs, or EMS improvements), state and local police, local governments, and interested private groups. Participation of all of these parties may be needed to identify the highest-priority locations and to carry out the most effective remedies. • Does the highway network screening process have any influence on the overall state highway capital and maintenance programs? For example, when the state plans and designs its major highway capacity projects or its pavement resurfacing program, does information about high-hazard locations influence priorities and project designs? Or, alternatively, is the screening used solely to direct the spending of earmarked safety funds? • Does highway network screening influence the priorities and practices of agencies outside the state department of transportation—state police, local police, local roads programs, and metropolitan planning organizations? • Have state hazard elimination programs achieved an appropriate balance between spot safety improvements (i.e., improvements to short segments or individual intersections) and 

Case Studies of Safety Interventions 145 corridor-based safety improvements (i.e., broadly based improvement packages for extended road sections with the highest identified risk levels)? • How can the impact of the hazard elimination program and related safety analysis and planning activities be evaluated, either on a project-by-project basis or cumulatively over a period of years for an entire state? • If evidence from the states with the best programs or from other countries shows that hazard eliminations could make a much greater contribution to reducing traffic injuries, what strategy can be used to reform the lagging programs and increase the resources available to them? The restructured HSIP of SAFETEA-LU was intended to raise the stature of the program by increasing funding and by linking it to comprehensive state highway safety plans. Has the new federal structure enhanced the performance of the state programs? REFERENCES Abbreviations ABATE Alliance of Bikers Aimed Toward Education ACEM Association des Constructeurs Européens des Motocycles DfT Department for Transport ECMT European Council of Ministers of Transport ERSO European Road Safety Observatory ETSC European Transport Safety Council FHWA Federal Highway Administration GAO General Accounting Office GHSA Governors Highway Safety Association IIHS Insurance Institute for Highway Safety MADD Mothers Against Drunk Driving NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board ODOT Oregon Department of Transportation OECD Organisation for Economic Co-operation and Development ONISR Observatoire National Interministériel de Sécurité Routière TRB Transportation Research Board USDOT U.S. Department of Transportation Aarts, L., and I. van Schagen. 2006. Driving Speed and the Risk of Road Crashes: A Review. Accident Analysis and Prevention, Vol. 38, No. 2, pp. 215–224. ABATE of California. n.d. History of ABATE. http://www.abate.org/aboutus/history/. ACEM. 2006. Safety Innovations by Industry: Indicative Overview. http://www.acem.eu/media/d_Annex3IndicativeoverviewofSafetyInnovations_61541.pdf. ACEM. 2009a. Contribution to the Public Consultation on a Proposal for a Framework Regulation of the European Parliament and of the Council on Type-Approval of Two- and Three-Wheel Motor Vehicles. Feb. 23. ACEM. 2009b. News from the Motorcycle Industry in Europe. No. 18, Feb. www.acem.eu. ACEM. 2010. Protective Equipment for Riders. March. Arizona Department of Public Safety. n.d. Photo Enforcement Program. http://www.azdps.gov/Services/Photo_Enforcement/. 

146 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Bashem, W. M., and P. H. Mengert. 1974. The Effects of the Energy Crisis on Rural Roads in Maine. Public Roads, Dec., pp. 100–105. Blomberg, R. D., and A. M. Cleven. 2006. Pilot Test of Heed the Speed, a Program to Reduce Speeds in Residential Neighborhoods. National Highway Traffic Safety Administration, Aug. Blomberg, R. D., F. D. Thomas III, and A. M. Cleven. 2008. Increasing Seat Belt Use Through State- Level Demonstration Projects: A Compendium of Initial Findings. National Highway Traffic Safety Administration, Aug. Blomberg, R. D., F. D. Thomas III, and A. M. Cleven. 2009. Innovative Seat Belt Demonstration Programs in Kentucky, Mississippi, North Dakota, and Wyoming. National Highway Traffic Safety Administration, March. Breen, J., E. Howard, and T. Bliss. 2007. An Independent Review of Road Safety in Sweden. Dec. CISR. 2006. Dossier de Presse. July 6. City of Scottsdale. n.d. Photo Enforcement Program. http://www.scottsdaleaz.gov/photoradar.asp. Compton, R., and A. Berning. 2009. Traffic Safety Facts Research Note: Results of the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers. National Highway Traffic Safety Administration, July. Delaney, A., H. Ward, M. Cameron, and A. F. Williams. 2005. Controversies and Speed Cameras: Lessons Learnt Internationally. Journal of Public Health Policy, Vol. 26, pp. 404–415. DfT. 2007. Road Casualties Great Britain 2006. Sept. DfT. 2008. Road Casualties Great Britain 2007. Sept. Dinh-Zarr, T. B., D. A. Sleet, R. A. Shults, S. Zaza, R. W. Elder, J. L. Nichols, R. S. Thompson, and D. M. Sosin. 2001. Reviews of Evidence Regarding Interventions to Increase the Use of Safety Belts. American Journal of Preventive Medicine, Vol. 21, No. 4, Supplement 1, Nov., pp. 48–65. Elder, R. W., R. A. Shults, D. A. Sleet, J. L. Nichols, S. Zaza, and R. Thompson. 2002. Effectiveness of Sobriety Checkpoints for Reducing Alcohol-Involved Crashes. Traffic Injury Prevention, Vol. 3, No. 4, pp. 266–274. ERSO. 2007. Traffic Safety Basic Facts 2006: Motorcycles and Mopeds. European Commission, Jan. ETSC. 2005. Road Safety Audit. ETSC Fact Sheet No. 5, July. Evans, L. 2004. Traffic Safety. Science Serving Society, Bloomfield Hills, Mich. Farmer, C. F. 2008. Crash Avoidance Potential of Five Vehicle Technologies. Insurance Institute for Highway Safety, June. Fell, J. C., J. H. Lacey, and R. B. Voas. 2004. Sobriety Checkpoints: Evidence of Effectiveness Is Strong, but Use Is Limited. Traffic Injury Prevention, Vol. 5, No. 3, Sept., pp. 220–227. Fell, J. C., and R. B. Voas. 2006. The Effectiveness of Reducing Illegal Blood Alcohol Concentration (BAC) Limits for Driving: Evidence for Lowering the Limit to .05 BAC. Journal of Safety Research, Vol. 37, pp. 233–243. FHWA. 1996. 1996 Annual Report on Highway Safety Improvement Programs. FHWA. 1997. Highway Statistics Summary to 1995. July. FHWA. 2001. Highway Statistics 2000. FHWA. 2005. Highway Safety Improvement Program: Questions and Answers. Sept. 14. FHWA. 2006. Highway Statistics 2005. FHWA. 2010. Highway Statistics 2008. FHWA. n.d. a. Fatality Rate by Road Function Class Table. http://safety.fhwa.dot.gov/speedmgt/data_facts/. FHWA. n.d. b. Road Safety Audits (RSA). http://safety.fhwa.dot.gov/rsa/. GAO. 1991. Highway Safety: Motorcycle Helmet Laws Save Lives and Reduce Costs to Society. July. GHSA. 2005. Survey of the States: Speeding. GHSA. n.d. a. Drunk Driving Laws. www.ghsa.org/stateinfo/laws/impaired_laws.html. GHSA. n.d. b. State Highway Safety Grant Programs. www.ghsa.org/html/stateinfo/grants/index.html. Glassenbrenner, D., and J. Ye. 2006. Motorcycle Helmet Use in 2006—Overall Results. National Highway Traffic Safety Administration, Nov. 

Case Studies of Safety Interventions 147 Gordon, P. 2007. Mayor Gordon Says Heed the Speed. Press release, March 29. www.philgordon.org. Harder, K. A., and J. R. Bloomfield. 2007. Evaluating the Effectiveness of the Minnesota Speed Management Program. Minnesota Department of Transportation, May. Harsha, B., and J. Hedlund. 2007. Changing America’s Culture of Speed on the Roads. In Improving Traffic Safety Culture in the United States: The Journey Forward, AAA Foundation for Traffic Safety, April. Harwood, D. W., D. K. Gilmore, and K. M. Bauer. 2010. U.S. Road Assessment Program—Phase III: Final Report. AAA Foundation for Traffic Safety, May. Haworth, N. L., and I. R. Johnston. 2004. Why Isn’t the Involvement of Alcohol in Road Crashes in Australia Lower? Abstract. Presented at 17th International Conference on Alcohol, Drugs, and Traffic Safety, Glasgow, United Kingdom. Hedlund, J. 2007. Traffic Safety in the United States—Timeline of Notable Events: Draft. March 3. http://www.lifesaversconference.org/webfiles2007/Hedlund1.doc. Hedlund, J., S. H. Gilbert, K. Ledingham, and D. Preusser. 2008. How States Achieve High Seat Belt Use Rates. National Highway Traffic Safety Administration, Aug. Hedlund, J. H., B. Harsha, and W. A. Leaf. 2007. Countermeasures That Work: A Highway Safety Countermeasures Guide for State Highway Safety Offices. National Highway Traffic Safety Administration. Hedlund, J. H., B. Harsha, W. A. Leaf, A. H. Goodwin, W. L. Hall, J. C. Raborn, L. J. Thomas, and M. E. Tucker. 2009. Countermeasures That Work: A Highway Safety Countermeasures Guide for State Highway Safety Offices: Fourth Edition. National Highway Traffic Safety Administration. Hendricks, D. L., J. C. Fell, and M. Freedman. 2001. The Relative Frequency of Unsafe Driving Acts in Serious Traffic Crashes: Summary Technical Report. National Highway Traffic Safety Administration, Jan. IIHS. 2000. How State Laws Measure Up. Status Report, Vol. 35, No. 10, Dec. 20, pp. 1–7. IIHS. 2005. Status Report, Vol. 40, No. 4, April 2. IIHS. 2006. How State Laws Measure Up: As of March 2006. IIHS. 2007. Q&A: Motorcycle Helmet Use Laws as of June 2007. http://www.iihs.org/research/qanda/helmet_use.html#10. IIHS. 2009a. How State Laws Measure Up. Dec. http://www.iihs.org/laws/measureup.aspx. IIHS. 2009b. Safety Belt Use Laws: October 2009. IIHS. 2010. Safety Belt Use Laws: October 2010. http://www.iihs.org/laws/SafetyBeltUse.aspx. Johnston, I. 2006. Halving Roadway Fatalities: A Case Study from Victoria, Australia, 1989–2004. Federal Highway Administration, April. Jones, M. M., and R. Bayer. 2007. Paternalism and Its Discontents: Motorcycle Helmet Laws, Libertarian Values, and Public Health. American Journal of Public Health, Vol. 97, No. 2, Feb., pp. 208–217. Kahane, C. J. 2000. Fatality Reduction by Safety Belts for Front-Seat Occupants of Cars and Light Trucks: Updated and Expanded Estimates Based on 1986–99 FARS Data. National Highway Traffic Safety Administration, Dec. Kemper, W. J., and S. R. Byington. 1977. Safety Aspects of the National 55 MPH Speed Limit. Public Roads, Sept., pp. 58–67. Kraay, J. H. 2002. The Netherlands Traffic and Transport Plan: Road Safety with Special Focus on Speed Behavior. Presented at International Cooperation on Theories and Concepts in Traffic Safety Workshop, Nagoya, Japan. www.ictct.org. LaHeist, W. G. 1998. Highway Traffic Assessment: A Summary of Findings in Ten States. National Highway Traffic Safety Administration, June. Lave, C., and P. Elias. 1994. Did the 65 mph Speed Limit Save Lives? Accident Analysis and Prevention, Vol. 26, No. 1, Feb., pp. 49–62. Li, X., L. Yu, and V. Garg. 2004. Evaluation of the Overall Effectiveness of Highway Safety Improvement Projects at the National Level. In Applications of Advanced Technologies in 

148 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Transportation Engineering (K. C. Sinha, T. F. Fwa, R. L. Cheu, and D.-H. Lee, eds.), American Society of Civil Engineers, Reston, Va. Lundegaard, K. 2004. Risky Riders: Touting Freedom, Bikers Take Aim at Helmet Laws. Wall Street Journal, Nov. 30, p. A1. MADD. n.d. Sobriety Checkpoint FAQs. http://www.madd.org/Drunk-Driving/Drunk- Driving/Campaign-to-Eliminate-Drunk-Driving/Law-Enforcement/Sobriety-Checkpoint-FAQs.aspx. McKnight, J., and A. S. McKnight. 1994. The Effects of Motorcycle Helmets upon Seeing and Hearing. National Highway Traffic Safety Administration, Feb. Neiman, M. 2007. Motorcycle Helmet Laws: The Facts, What Can Be Done to Jump-Start Helmet Use, and Ways to Cap the Damages. http://works.bepress.com/melissa_neiman/1/. Nerup, P., P. Salzberg, J. VanDyk, L. Porter, R. Blomberg, F. D. Thomas, and L. Cosgrove. 2006. Ticketing Aggressive Cars and Trucks in Washington State: High Visibility Enforcement Applied to Share the Road Safely. National Highway Traffic Safety Administration, May. Neuman, T. R., K. L. Slack, K. K. Hardy, V. L. Bond, R. D. Foss, A. H. Goodwin, J. Sohn, D. J. Torbic, D. W. Harwood, I. B. Potts, R. Pfefer, C. Raborn, and N. D. Lerner. 2009. NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan: Volume 23: A Guide for Reducing Speeding-Related Crashes. Transportation Research Board of the National Academies, Washington, D.C. New York State Governor’s Traffic Safety Committee. 2008. New York State Highway Safety Strategic Plan: FFY 2009. Newton, C. 2010. Arizona to Eliminate Speed-Enforcement Cameras on Freeways. Arizona Republic, May 6. http://www.azcentral.com/news/articles/2010/05/06/20100506arizona-to-eliminate-speed- cameras.html. NHTSA. 1998. Without Motorcycle Helmets We All Pay the Price. Aug. NHTSA. 2003. Motorcycle Safety Program. Jan. NHTSA. 2004. Motorcycle Effectiveness Revisited. March. NHTSA. 2005a. Analysis of Speeding-Related Fatal Motor Vehicle Traffic Crashes. June. NHTSA. 2005b. Motorcycle Helmet Use Laws. March. NHTSA. 2007a. The Nation’s Top Strategies to Stop Impaired Driving. Feb. NHTSA. 2007b. Traffic Safety Facts 2005. NHTSA. 2007c. Traffic Safety Facts: 2005 Data: Motorcycles. NHTSA. 2007d. Traffic Safety Facts: 2005 Data: Speeding. NHTSA. 2007e. Traffic Safety Facts 2006. NHTSA. 2008a. Traffic Safety Facts 2007. NHTSA. 2008b. Traffic Safety Facts Research Note: Seat Belt Use in 2008—Overall Results. Sept. NHTSA. 2008c. Traffic Safety Facts Traffic Tech—Technology Transfer Series: How States Achieve High Seat Belt Use Rates. Aug. NHTSA. 2009a. Motorcycle Helmet Use in 2009—Overall Results. Dec. NHTSA. 2009b. Seat Belt Use in 2009—Overall Results. Sept. NHTSA. 2009c. Traffic Safety Facts 2008. NHTSA. 2009d. Traffic Safety Facts Crash-Stats: Seat Belt Use in 2008—Use Rates in the States and Territories. April. NHTSA. 2009e. Traffic Safety Facts Research Note: Seat Belt Use in 2009—Overall Results. Sept. NHTSA. 2009f. Traffic Safety Facts Research Note: Seat Belt Use in Rear Seats in 2008. May. NHTSA. 2010. Highlights of 2009 Motor Vehicle Crashes. Aug. NHTSA. n.d. SAFETEA-LU Fact Sheets. http://www.atssa.com/galleries/default- file/NHTSA%20FACT%20SHEETS.pdf. Nichols, J. L., K. A. Ledingham, and D. F. Preusser. 2007. Effectiveness of the May 2005 Rural Demonstration Program and the Click It or Ticket Mobilization in the Great Lakes Region: First Year Results. National Highway Traffic Safety Administration, April. 

Case Studies of Safety Interventions 149 Noland, R. B. 2003. Traffic Fatalities and Injuries: The Effect of Changes in Infrastructure and Other Trends. Accident Analysis and Prevention, Vol. 35, No. 4, July, pp. 599–611. NTSB. 2000. Safety Report: Actions to Reduce Fatalities, Injuries, and Crashes Involving the Hard Core Drinking Driver. June 27. ODOT. 2007. Highway Safety Program Guide. Feb. OECD and ECMT. 2006. Speed Management: Summary Document. Joint Transport Research Centre. OECD and International Transport Forum. 2006. Country Reports on Road Safety Performance. July. ONISR. 2005. French Road Safety Policy. ONISR. 2006. Observatoire des Vitesses: Second Quadrimestre 2006. Oct. 20. http://www.securiteroutiere.gouv.fr/IMG/pdf/observatoire_vitesse.pdf. ONISR. 2008. La Sécurité Routière en France: Bilan de l’Année 2007. Dec. ONISR. 2009a. La Sécurité Routière en France: Bilan de l’Année 2008. http://www2.securiteroutiere.gouv.fr/infos-ref/observatoire/accidentologie/le-bilan-de-l.html. ONISR. 2009b. Observatoire des Vitesses: Premier Quadrimestre 2009. July. Pastore, A. L., and K. Maguire (eds.). n.d. Sourcebook of Criminal Justice Statistics Online. http://www.albany.edu/sourcebook/. Preusser, D. F., J. H. Hedlund, and R. G. Ulmer. 2000. Evaluation of Motorcycle Helmet Law Repeal in Arkansas and Texas. National Highway Traffic Safety Administration, Sept. SafetyNet. 2005. Traffic Safety Basic Facts 2004: Motorcycles and Mopeds. European Commission. Savage, M., M. Sundeen, and J. Majeur. 2007. Traffic Safety and Public Health: State Legislative Action 2006. Transportation Series, No. 31, National Conference of State Legislatures, March. Savage, M., A. Teigen, and N. Farber. 2010. Traffic Safety and Public Health: State Legislative Action 2009. Transportation Series, No. 34, National Conference of State Legislatures, Feb. Schoenebeck, S. 2007. Alcohol Related Road Accidents in Germany—Status Till 2005. Proc., International Council on Alcohol, Drugs and Traffic Safety. http://www.icadts2007.org/scientific/proceedings/index.html. Servadei, F., C. Begliomini, E. Gardini, M. Giustini, F. Taggi, and J. Kraus. 2003. Effect of Italy’s Motorcycle Helmet Law on Traumatic Brain Injuries. Injury Prevention, Vol. 9, No. 3, pp. 257–260. Shankar, U., and C. Varghese. 2006. Recent Trends in Fatal Motorcycle Crashes: An Update. National Highway Traffic Safety Administration, June. Shults, R. A., R. W. Elder, D. A. Sleet, J. L. Nichols, M. O. Alao, V. G. Carande-Kulis, S. Zaza, D. M. Sosin, and R. S. Thompson. 2001. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. American Journal of Preventive Medicine, Vol. 21, No. 4, Supplement 1, Nov., pp. 66–88. Smiley, A. 2008. Driver Behavior: A Moving Target. TR News, No. 254, Jan.–Feb., pp. 19–24. Stone, J. L. 2004. Statement of Judith Lee Stone, President, Advocates for Highway and Auto Safety: Special Commendation to Louisiana Legislature and Governor Blanco for Reinstatement of Lifesaving All-Rider Helmet Law. Advocates for Highway and Auto Safety, June 18. Subramanian, R. 2002. Transitioning to Multiple Imputation—A New Method to Impute Missing Blood Alcohol Concentration (BAC) Values in FARS. National Highway Traffic Safety Administration, Jan. Swedish Road Administration. 2009. Årsredovisning 2008 [Annual Report 2008]. Sweedler, B. M. 2007. Worldwide Trends in Alcohol and Drug Impaired Driving. Proc., International Council on Alcohol, Drugs and Traffic Safety. http://www.icadts2007.org/scientific/proceedings/index.html. Sweedler, B. M., M. B. Biecheler, H. Laurell, G. Kroj, M. Lerner, M. P. M. Mathijssen, D. Mayhew, and R. J. Tunbridge. 2004. Worldwide Trends in Alcohol and Drug Impaired Driving. Traffic Injury and Prevention, Vol. 5, No. 3, Sept., pp. 175–184. Task Force on Community Preventive Services. 2005. Guide to Community Preventive Services. Oxford University Press, New York. Task Force on Community Preventive Services. n.d. Motor Vehicle Occupant Injury. http://www.thecommunityguide.org/mvoi/default.htm. 

150 Special Report 300: Achieving Traffic Safety Goals in the United States: Lessons from Other Nations Thiel, C. 2003. The Federal 0.08 BAC Requirement and the Potential Loss of Highway Funding. State Notes, Michigan Senate Fiscal Agency, May–June. Traffic Safety Center, University of California at Berkeley. 2002. Getting People to Buckle Up. Traffic Safety Center Online Newsletter, Vol. 1, No. 2, Dec. TRB. 1987. Special Report 214: Designing Safer Roads: Practices for Resurfacing, Restoration, and Rehabilitation. National Research Council, Washington, D.C. TRB. 1998. Special Report 254: Managing Speed: Review of Current Practice for Setting and Enforcing Speed Limits. National Research Council, Washington, D.C. TRB. 2003. Special Report 271: Freight Capacity for the 21st Century. National Academies, Washington, D.C. TRB. 2003–2009. NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volumes 1–23. National Academies, Washington, D.C. Ulmer, R. G., and V. S. Northrup. 2005. Evaluation of the Repeal of the All-Rider Motorcycle Helmet Law in Florida. National Highway Traffic Safety Administration, Aug. Ulmer, R. G., and D. F. Preusser. 2003. Evaluation of the Repeal of Motorcycle Helmet Laws in Kentucky and Louisiana. Oct. U.S. Department of Justice. 1989. Brief for the Respondents in Opposition; State of Nevada, Petitioner, v. Samuel K. Skinner, Secretary of Transportation, et al., in the Supreme Court of the United States. USDOT. 2007. Fiscal Year 2008 Budget in Brief: National Highway Traffic Safety Administration. www.dot.gov/bib2008/bibpart07nhtsa.htm. usRAP. 2008. Phase III Plans. http://www.aaafoundation.org/pdf/usRAPphaseIIIplans.pdf. Washington, S., K. Shin, and I. van Schalkwyk. 2007. Evaluation of the City of Scottsdale Loop 101 Photo Enforcement Demonstration Program. Arizona Department of Transportation, Nov. Wilmot, C. G., and M. Khanal. 1999. Effect of Speed Limits on Speed and Safety: A Review. Transport Reviews, Vol. 19, No. 4, Oct., pp. 315–399. Wilson, E. M., and M. E. Lipinski. 2004. NCHRP Synthesis of Highway Practice 336: Road Safety Audits. Transportation Research Board of the National Academies, Washington, D.C. Yowell, R. O. 2005. The Evolution and Devolution of Speed Limit Law and the Effect on Fatality Rates. Review of Policy Research, Vol. 22, No. 4, pp. 501–518.