Surface Transportation Environmental Research: A Long-Term Strategy -- Special Report 268 (2002)

The next 25 years will present a significant challenge for transportation professionals as a result of the anticipated growth of the U.S. population, economic expansion, and increases in passenger-miles traveled (see Box 1-1). As the population grows and the economy expands, Americans will become increasingly more mobile and will expect policymakers and transportation professionals to institute transportation services that are capable of accommodating increasing demand in a manner that is not only efficient and inexpensive, but also both socially and environmentally sound.

While it is true that Americans consistently rank mobility and easy access to transportation¹ as a top priority,² they also value the environment. Tolerance for the loss of open space, community disruption, unhealthy air quality, and increased greenhouse gases³ is diminishing. In this context, the Surface Transportation Environmental Cooperative Research Program

Advisory Board (Advisory Board) was formed to recommend a national agenda of environmental research related to surface transportation.⁴

The Advisory Board was formally charged with recommending a national agenda of energy and environment research for the surface transportation community.⁵ During the board’s first meeting, however, it became apparent

that two additional components would have to be incorporated into the board’s formal charge. First, the board determined that a viable agenda for environmental research related to surface transportation would have to include a focus on planning processes and methods. Unless environmental concerns are factored into the transportation planning process, the secondary and cumulative effects of system-level transportation decisions on larger-scale environmental systems will remain insufficiently addressed in the early stages of the process. The Advisory Board therefore agreed to amend its charge to encompass development of a national agenda for environmental and planning research related to surface transportation, with the latter focus being directed specifically at the overlap between planning processes and environmental issues. The Advisory Board’s statement of task is presented in Box 1-2.

Second, the Advisory Board believed that the identification of research priorities would be a productive exercise only if existing research programs

were structured to implement the new priorities, or a new cooperative research program were created. To be productive, a long-term research agenda would have to be part of a long-term research strategy. Therefore, the Advisory Board’s efforts were informed throughout by a long-term perspective on research needs.

Concerns about transportation’s impacts on the natural and built environments are hardly new. For example, in the early days of the United States, the building of canals interconnecting waterways and the operation of steamships adversely altered fish populations. The expansion of railroads westward was a factor in the near extinction of the American bison (TRB 1997). Coal-fired locomotives were a source of soot in cities and fires in surrounding farm fields and forests. And in many communities, horse manure had become a severe and growing problem by the late 1800s (FHWA 1976).

The rapid growth of cities during the industrial revolution of the late 19th and early 20th centuries led to concerns about congestion and over-crowding, and to a growing expectation that transportation systems should help alleviate such ills. At the first national conference on city planning held in Washington, D.C., in 1909, urban planners were implored to develop subways and public transit routes to the outer edges of city boundaries. Transportation was seen as the key to improving living conditions, lowering density, and generally enhancing the state of the human environment (Wachs 1999).

Ultimately, horses—and all the travails associated with them as a mode of transportation (e.g., horse manure, disease-infested horse flies)—would be replaced with clean, sterile machines. With the introduction of urban electric streetcars and then the automobile, many believed the transportation systems of the future would be clean as well as efficient. Indeed, both technologies greatly improved sanitation in addition to mobility and access. It would not be until the 1940s that motor vehicle exhaust would first become associated with urban smog and agricultural crop damage (TRB 1997).

The emergence of the automobile (and for freight transport, the truck) transformed American transportation systems. The growing popularity of the

automobile⁶ generated demand for better roads⁷ and calls for the federal government to become immersed in road development. In 1916 Congress passed the first federal-aid highway legislation—the Federal-Aid Road Act of 1916, establishing the Federal-Aid Highway Program. This act provided for the distribution of federal funds to state highway agencies, creating a financial incentive for the development of a system of improved farm-to-market, intercity, and interstate roads (FHWA 1999). The states also developed major road building and improvement programs, and quickly followed Oregon’s lead in adopting a gasoline tax for highway finance.⁸ During the same period, mass production of the automobile in the United States made it an affordable means of transport to growing numbers of Americans, who quickly adopted the new technology and began to use it for recreational, goods-carrying, and commuting purposes.

During the Great Depression, automobile purchases declined and expenditures on highway construction slowed, even though road building was used to create jobs and to stimulate the economy. Both automobile manufacturing and road building came to a halt during World War II as materials and industrial capacity were diverted to the war effort (Robinson 1971). When the war ended, housing and automobiles were in heavy demand. Automobile ownership skyrocketed, suburban land development flourished as new homes were built on former greenfields, and state and federal governments began building vast new highway systems (Anderson and Tregoning 1998). New expressways designed to meet suburb-to-city commuting patterns were built; beltways were added to allow long-distance travel to bypass city centers. States led the way with turnpikes and toll roads built in the late 1940s and early 1950s.⁹

Interstate highways, funded with a 90 percent federal share after passage of the Interstate Highway Act of 1956, became the centerpiece of American surface transportation, and land development patterns quickly reflected the greatly increased accessibility provided by the highways. The Interstate program both

supported suburban development and enabled it to accelerate; new forms of development, including the shopping mall and the office park, joined suburban housing tracts in areas served by new highways. By the late 1970s, commercial development lined the periphery of most North American cities (Anderson and Tregoning 1998).

In central cities and inner suburbs, however, new roads were not as easily embraced. In San Francisco, the elevated Embarcadero Freeway blocked city views of the historic Ferry Building; outraged citizens prevented further freeway construction. In New Orleans, a proposal to build an Interstate through the Vieux Carre was rejected. In Memphis, plans to build an Interstate through Overton Park were halted through litigation. Los Angeles’ proposals to build freeways through the low-income and minority neighborhoods of Watts, Compton, and Hacienda Park were tabled after massive protests. And Boston’s plans for an Inner Belt and a Southwest Expressway were scrapped after a massive restudy. Concerns about the potential adverse social and environmental consequences of highways were increasingly voiced: impacts on community cohesion, historical and cultural resources, and the natural environment became a rallying point for opposition to urban Interstates.

These growing concerns led to passage of the National Environmental Policy Act (NEPA) in the last days of 1969; thereafter, all federally funded highway projects were subject to environmental review. Air pollution from automobiles was a particular concern. With passage of the Clean Air Act of 1970 (and the subsequent amendments in 1977 and 1990), state implementation plans (SIPs) were required to document transportation’s contributions to air pollution and to set forth strategies for reducing transport emissions, complementing federal requirements that greatly reduced emissions from new cars and trucks. While the federal government intervened directly on new-car emissions (and subsequently on energy consumption), and state environmental agencies and later metropolitan planning organizations (MPOs) often took the lead in developing SIPs, state highway agencies themselves were given an environmental mandate in the Federal-Aid Highway Act of 1972. That act, which required the detailed evaluation and consideration of social, economic, and environmental effects and increased public involvement in highway decision making, along with NEPA, led many state highway agencies to increase research and development on environmentally sound transportation planning and design practices (FHWA 1976).

As the Interstates were expanding and environmental and energy concerns were emerging as key public policy issues, the plight of American transit sys-

tems also was beginning to receive attention. The heyday of transit had predated the automobile; many systems had begun losing market share by the 1920s (Jones 1985). During World War II, however, heavy usage with little investment in the systems added to their wear and tear,¹⁰ and when fuel and cars became readily available following the cessation of hostilities, many transit riders became automobile commuters.

Transit advocates argued for a federal role in funding transit, both to help rejuvenate the systems and to provide a mobility option that many deemed better suited to dense urban areas. In 1964, Congress responded with the Urban Mass Transportation Act, providing funding for capital grants to upgrade and expand transit services. Successive laws expanded the scope of the federal transit program to include formula-based grants to operators, as well as discretionary capital grants for major new starts, and to provide for rural transit and paratransit. New rail systems were built in several cities, including Washington, D.C.; Atlanta; Los Angeles; Portland, Oregon; Sacramento; and the San Francisco Bay Area. Systems were expanded in many other cities, including Pittsburgh and Boston. Bus services were started or expanded in a number of cities, such as Houston and Phoenix. Some of the services replaced the old streetcar systems that had been dismantled in the 1950s. While these investments generally produced ridership increases, transit’s share of travel, even for work trips, remained in the single digits except in a handful of older, denser cities, including New York, Boston, Philadelphia, Chicago, and San Francisco. Still, transit’s importance to city centers, its service to those who cannot or do not drive, and its relatively benign environmental impacts continue to attract support.

The story of freight transport in the United States has many parallels with the history of passenger transport. Freight was first transported via waterways, as well as along roads of varying quality. The advent of canals and then railroads in the early to mid-1800s opened up vast new territories for economic development and in so doing transformed the American landscape. Government helped fund the new transportation systems, both directly and through the provision of land. Later, concerned about economic impacts, government stepped in to regulate industrial organizations, tariffs, and conditions of service provided by the powerful railroads. Trucking in its turn was subject to economic regulation and conditions of operation. Yet competition from trucking grew as the automotive

industry developed and roads were improved and expanded, eventually causing many railroads to face financial difficulties. Partial deregulation, reorganization, and consolidation helped revive some railroads, though others (most notably the Penn Central) ended in bankruptcy. Deregulation of trucking, meanwhile, led to vast numbers of new entrants into the market, and to concerns about the resulting community and environmental impacts.

Today the nation’s surface transportation system encompasses 3.9 million miles of roads, 1.4 million miles of oil and natural gas pipelines, 123,000 railroad route miles, and 26,000 miles of navigable waterways; in addition, 508 public transit operators are located in 316 urban centers. These facilities accommodate more than 5 trillion passenger-miles of travel and 3 trillion ton-miles of freight each year. Approximately 200 million automobiles and light trucks— an average of 1.8 motor vehicles per household—account for 87 percent of total vehicular passenger-miles traveled (U.S. Department of Transportation Report to Congress, 4th edition), and the trend is increasing. Specifically, in 1970 Americans averaged 4,485 automobile-miles per person per year; by 1993, this number had increased 41 percent to an average of 6,330 automobile-miles per person. Between 1983 and 1990, the average trip length for all purposes increased from 8.68 to 9.45 miles.

This growth in transportation activity reflects and supports the nation’s economic development and the active social, cultural, and recreational lives of the nation’s populace. At the same time, environmental interventions have helped make this growth more acceptable than would otherwise have been the case. Gains are particularly visible in the areas of air quality, with highway emissions having declined by almost 15 percent—from 74.4 million tons in 1993 to 63.7 million tons in 1999. This improvement can be attributed to advances in vehicle fuel systems, the use of catalytic converters, and the development of cleaner-burning fuels. Progress has also been made in energy efficiency, with the average fuel economy of automobiles and light trucks having increased by 54 percent and 63 percent, respectively, between 1975 and 1998. Less well known, perhaps, are the gains in water quality achieved through treatment of highway runoff; the reductions in roadkill due to new animal bypasses and tunnels under highways and railroads; and the decrease in highway noise attributable to the advent of noise barriers, vehicle controls (including quieter engines and improved mufflers), and improved vehicle maintenance (DOT 2000).

Nevertheless, much remains to be done—both problems to be solved and opportunities to be seized:

• While road building has generally slowed now that the Interstate highway system is complete, new roads are still being added both in the high-growth states of the south and west and in many other areas of the country where population and jobs continue to move to the suburbs and beyond. Designing these roads to be environmentally benign will require new planning approaches and new construction and operation methods. Further, as increasing numbers of existing transport facilities (roads, bridges, terminals) require reconstruction, there will be opportunities to introduce new designs that are more environmentally friendly for the natural or built environment.

• The Environmental Protection Agency (EPA) is currently predicting that by 2007 the downward trend in emissions of ozone precursors (nitrogen oxides and volatile organic compounds) will level off and subsequently begin to increase (nitrogen oxides in 2020 and volatile organic compounds after 2007) (EPA 2000).¹¹ This is cause for concern as epidemiologists have confirmed a link between air pollution and adverse impacts on human health; for example, ground-level ozone has been associated with weakened respiratory functioning, lung inflammation, and increased incidence of childhood asthma. Ongoing research and development will be required to devise additional means of reducing emissions to acceptable levels.

• If energy costs to build infrastructure, produce fuel, and manufacture vehicles were factored into the equation, transportation would account for more than 70 percent of total domestic oil consumption (Davis, 2000). Currently, the United States imports more than half of its oil reserves. Given the uncertainties associated with foreign supplies, growth in demand in other countries, and the finite world supply of oil, the development of methods to reduce petroleum dependence and/or increase energy efficiency may be a necessity.

• Motor vehicles are estimated to be responsible for approximately 20 percent of all U.S. emissions of carbon dioxide, a greenhouse gas¹² (EIA

2000). Additionally, 16 percent of all U.S. emissions of chlorofluorocarbons (Burwell et al. 1991), a critical element in the destruction of the ozone layer, can be attributed to motor vehicles. These impacts on the environment are increasingly receiving worldwide attention, and the United States needs strategies for managing greenhouse gases and ozone depletors that suit the nation’s own social, economic, and political realities.

• Releases of zinc, cadmium, copper and nickel, chromium, and iron into the environment result in part from the abrasion of tires and brake linings. Deposition of these pollutants near highways can result in contamination of surface dust and soil. Moreover, leakage of brake fluid, antifreeze compounds, lubricating oil, engine oil, and grease onto the highway surface can lead to the contamination of surface water and groundwater. The chain of events of emission, dispersion, deposition, and removal of automotive pollutants—and the resulting impact on the natural environment in the short term—has been well-documented (Ball et al. 1991; EPA 2001), if not well understood. More work is needed to devise methods of reducing these releases and their environmental impacts. Moreover, relatively little is known about the long-term effects of these releases.

• It is increasingly recognized that cumulative, long-term impacts are important and may not be readily understood or managed within the context of the current system. For example, air pollutants when deposited frequently pollute the surrounding soil and water supply. Similarly, system effects are beginning to be understood; for example, it is now recognized that to protect endangered species, one must also protect their habitats and their genetic diversity. Furthermore, institutional approaches to the management of certain transportation-related environmental problems are proving to be inadequate, as in the case of air districts that do not span the pollutant transport area. These issues point to the need for research in a variety of fields, including basic scientific processes, management approaches, planning and forecasting methods, and institutional arrangements.

• Traffic congestion is a stressful experience for many Americans, causing elevated blood pressure and other stress-related health impacts, contributing to absence from work, and lowering tolerance for frustration (Burchell et. al. 1998). Congestion also increases vehicle operating costs, fuel consumption, and emissions and contributes to lost productivity. The Texas Transportation Institute estimated that in 1999, 50 major U.S. cities expended well over $78 billion in congestion-related costs—an estimate

that does not incorporate costs associated with stress-related illnesses. Strategies for managing congestion are being developed, but clearly more work is needed.

• Some population groups, including the young and some elderly, low-income, and disabled populations, have a limited ability to travel by automobile unassisted, and hence are transportation-disadvantaged in a society that uses automobiles for most trips. In addition, some communities are disproportionately impacted by transportation facilities and their adverse effects (e.g., increased traffic and pollution levels, barriers to physical activity, along with the actual physical division of communities by highway structures). Concern about these disparate impacts of transportation has led to calls for better planning methods, including means of developing community-sensitive alternatives, evaluating the distribution of benefits and costs, and providing for mitigation or amelioration of adverse effects.

• Public concerns regarding interactions between land use and transportation, as well as a broad range of community and environmental impacts, suggest the need to search for better methods of planning and achieving public involvement, new organizational approaches and assignments of responsibility, and new ways of managing the transportation system. □ New technologies—ranging from fuels and vehicles to methods for handling and displaying environmental data and forecasting transportation demand—offer possibilities for greatly improving transportation planning and transportation projects. But more work is needed to test, develop, and implement these technologies.

In short, research and development on transportation and the environment is needed to manage the problems of the coming decades. The potential for this research to pay off in substantial improvements and innovations is great.

A full decade ago, concerns about transportation and the environment led to the passage of landmark legislation—the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991. ISTEA marked a new era in transportation planning, outlining for the first time measures designed to foster a national transportation policy that transcended traditional modal issues, such as highway construction and transit subsidies, to focus on intermodal considerations

and address broader public policy concerns of economic efficiency and environmental quality. Specifically, the ISTEA policy statement declared:

To meet these new goals, ISTEA authorized the establishment of several new programs. For example, the Congestion Mitigation and Air Quality (CMAQ) program provided earmarked funding for major urban areas that had not attained the National Ambient Air Quality Standards. Another program provided funds specifically for enhancements to transportation projects, such as bicycle and pedestrian facilities, landscaping, and public amenities. Still another program funded research, development, and implementation of intelligent transportation systems (ITS) that use computers and information technology to improve transport capacity and safety.

The provisions in ISTEA that may have initiated the greatest change were those that called for the development of state and regional transportation plans and set forth land use and environmental factors to be considered in those plans. ISTEA assigned to MPOs lead responsibility for the regional transportation plans. State transportation agencies were to take the lead for key facilities (Interstates and a few others), as well as for plans and projects for those portions of the state outside of the major metropolitan areas. The state agencies were thus to work in partnership with the MPOs within the metropolitan areas.

ISTEA designated the U.S. Department of Transportation (DOT) as lead agency for defining national research goals and for serving as the coordinating body for transportation research for all modes. DOT was also charged with conducting an inventory of its own research activities and with developing a strategic framework for transportation research.

In September 1996, the U.S. General Accounting Office (GAO) conducted a review of DOT’s surface transportation research program to ascertain the status of transportation research prior to the reauthorization of ISTEA (GAO 1996). GAO concluded that DOT’s surface transportation research program was lacking in three principal areas:

• From fiscal year 1992 through fiscal year 1996, DOT had received a total of $2.9 billion in federal funding for surface transportation research. The vast majority of this funding had been allocated to highway-related research. Specifically, DOT had allocated $2.1 billion of the total research funding received to the Federal Highway Administration (FHWA), which in turn had allocated nearly half of those funds to the ITS program.

• GAO concluded that DOT had not succeeded in developing a strategic, integrated, or focused approach to surface transportation research as directed by ISTEA. Rather, the needs and activities of the individual modes were still governing DOT’s research initiatives, and little attention was being paid to the total surface transportation system.

• GAO noted that DOT was conducting very little long-term or high-risk surface transportation research. Unless the focus of DOT’s transportation research program were shifted, GAO cautioned, the transportation community would remain unprepared to fully address the goals espoused in ISTEA.

A targeted, long-term research strategy was clearly needed. The conclusion of the GAO report was that the investment in surface transportation research had been largely inadequate and to date had not reflected the significance of the issues involved. This situation persists today. Research on transportation and the environment is especially underfunded, with the environmental share of transportation research being a mere fraction of the total invested. In fiscal year 2000, DOT allocated less than $10 million of its $400 million annual research and development budget to addressing the environmental effects of transportation. If a long-term research strategy were formulated and sufficiently funded, it could provide a foundation for the development of solutions to some of today’s most pressing problems while allowing policymakers to prepare for the future.

The authors of the Transportation Equity Act for the 21st Century (TEA-21) were cognizant of the problems encountered in the implementation of ISTEA and recognized the need to develop a secure foundation for transportation– environment research. Thus as noted, the act called for the formation of the

Advisory Board to develop a research agenda that would guide the work of research institutions and establish the integrated research framework originally envisioned by the authors of ISTEA.

The Advisory Board identified six critical areas for the focus of its research agenda:

1. Human health,

2. Ecology and natural systems,

3. Environmental and social justice,

4. Emerging technologies,

5. Land use, and

6. Planning and performance measures.

The basis for selection of these six areas was the knowledge and collective expertise of the Advisory Board members, input received from federal agency representatives during board meetings, and the proceedings of a workshop held in September 2000 to solicit input on research priorities from experts within both the transportation and environment communities (see Appendix A for a summary of the workshop proceedings). Each of the six focus areas represents an obvious intersection point between transportation and the environment and typifies the inherent trade-offs involved. It should be noted that the Advisory Board did not attempt to provide a comprehensive list of topics for research, but rather aimed to identify research areas in which troublesome gaps in knowledge exist and further investment in research would pay off, significantly advancing the ability of transportation professionals to provide transportation systems that are socially and environmentally sound, as well as efficient and economical. It should also be noted that the six research areas identified by the Advisory Board are necessarily interconnected; this report is therefore intended to be read in its entirety, and individual chapters are not meant to stand alone.

The issues and the Advisory Board’s findings in the six focus areas are reviewed in turn in Chapters 2 through 7; the board’s recommendations for a research agenda in each area are presented at the conclusion of the respective chapter. Brief overviews of the six chapters are provided below. Three components necessary for establishing a comprehensive long-term research strategy for the surface transportation–environment arena are outlined in Chapter 8. In Appendix A a summary of the research priorities workshop is provided, and a matrix outlining the various components of four cooperative research programs reviewed for this study is given in Appendix B.

Transportation systems can affect human health through a variety of processes, including facility construction, operations, and maintenance, as well as vehicle fueling, operations, and scrappage. Significant health effects result from air pollution emissions, including air toxics; water pollution from runoff; deposition of emissions; leaks from solid waste disposal sites; and noise exposure. However, the links between transportation activities and human health are not yet fully understood or agreed upon. Additional research is needed to substantiate the linkages between exposure to emissions and health impacts, and to understand which transportation activities may pose the greatest threat to human health and thus should be modified. Research should address modal emissions and their implications for vehicle control strategies and transportation system designs, as well as transportation emissions of air toxics, their health impacts, and their policy implications. Research also should examine the potential health impacts from transportation runoff and deposition; the health effects of transportation noise exposure; and strategies for avoidance, minimization, and reduction of these impacts. Strategies for better understanding the economic value of health improvements and for incorporating health considerations into valuation methods also should be researched.

Historically, transportation’s impact on the environment has been measured in terms of human health; consequently, issues such as air pollution have received considerable attention. However, little research has been performed on the impacts of these same emissions, both short and long term, on natural systems (TRB 1997). Polls indicate that Americans value a clean environment, but also desire an efficient transportation system. To fully assess the trade-offs involved, both the transportation community and the American public need to understand the impacts of transportation on the environment in both the short and long terms. For example, if key species are reduced or eliminated as a result of the impacts of a transportation project, to what extent will biodiversity be altered? This question can be answered only through long-term monitoring and evaluation of the ecosystem. Another example involves the use of plantings near highways to reduce maintenance and create aesthetically attractive roadsides. To what extent will these plantings disrupt the natural environment and the functions provided by the ecosystem? There are many

examples of transportation’s impacts on the natural environment; this chapter provides broad insight into both the spatial and temporal issues associated with transportation and natural systems.

ISTEA and TEA-21 mandated increased public involvement and renewed attention to the economic, social, environmental, and energy effects of transportation decisions. Chapter 4 examines issues of equity in transportation, including the distribution of social, economic, and environmental impacts and related issues of environmental justice. Research is needed to understand differences in mobility, access, travel behavior, and travel preferences across socioeconomic groups; to develop improved planning approaches that better reflect and respond to community needs; to improve evaluation methods for examining the incidence of benefits and costs; to examine the differential impacts of current methods of finance and explore alternatives; and to understand the socioeconomic implications of emerging land development patterns and new transportation technologies. Research is also needed to develop innovative applications of technology that would improve the equity of the transport system in a cost-effective manner, and to devise improved methods for community involvement, collaborative planning, and conflict resolution.

In the not-too-distant future, the transportation industry is expected to incorporate two largely new sets of technologies: (a) propulsion technologies and fuels that will change the energy, pollution, and noise characteristics of vehicles; and (b) information, communication, and control technologies that will change how vehicles are used. The way these paths may unfold and how public policy may influence their direction to achieve enhanced environmental quality are two critical research questions. Research is needed on pathways for the transition to environmentally benign fuels and vehicles for passengers and freight; on user response to and demand for new technologies that could offer improved environmental performance; on possible applications of ITS technologies for environmental benefit; on policy instruments that would encourage the development of beneficial new technologies in a cost-effective manner and would respond to the impacts of new technologies as they gained market

share; and on institutional arrangements, including public–private partnerships for the research, development, and introduction of new transportation technologies and systems.

During the past three decades, both land consumption and vehicle-miles traveled have grown more rapidly than population in metropolitan areas across the United States. Empirical studies suggest that transportation investments have contributed to these trends, but many other factors, including housing policies, school quality, and consumer preferences, are also involved. (Deakin 1990). In response to concerns about sprawl, policymakers are implementing growth management and transportation initiatives, but the effects of these initiatives remain to be assessed. Focused, coordinated, and expanded research is needed on these topics, including the impacts of transportation investments on location decisions and land use; the costs and benefits of current development patterns and their transportation implications; the effects of the built environment on people’s willingness to walk, drive, or take public transportation; and the roles of public policy and institutional arrangements in current and prospective land use and transportation choices. Research is also needed to develop improved data, methods, and processes for considering land use, transportation, and the environment in an integrated, systematic fashion.

ISTEA and TEA-21 call for transportation planners to meet needs for transportation mobility in a manner that supports broader societal goals of economic competitiveness, social equity, and environmental sustainability. To accomplish this, transportation planners must develop a better understanding of travel needs and preferences, as well as a better set of planning methods for system analysis, forecasting, and decision making. Expanded research is needed on consumer choice processes and travel and activity patterns for both local and long-distance trips and both passenger and freight transportation; on the social, environmental, and economic benefits and costs of various transport options; on tools for measuring and forecasting complex transportation decisions for all modes and users; on performance measures and policy analysis approaches that can be used to gauge how well various strategies will accomplish desired

outcomes; and on methods for better linking public involvement, including citizens and private-sector interests, in the transportation planning and evaluation processes.

DOT U.S. Department of Transportation

EPA U.S. Environmental Protection Agency

EIA Energy Information Administration

FHWA Federal Highway Administration

GAO General Accounting Office

TRB Transportation Research Board

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Burwell, D. G., K. Bartholomew, and D. Gordon. 1991. Energy and Environmental Research Needs. In Special Report 231: Transportation, Urban Form, and the Environment, TRB, National Research Council, Washington, D.C., pp. 81–99.

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FHWA. 1999. Report to the Nation, Connecting America. U.S. Department of Transportation, Washington, D.C.

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Jones, D. W. 1985. Urban Transit Policy: An Economic and Political History. Prentice-Hall, Englewood Cliffs, N.J.

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TRB. 1997. Special Report 251: Toward a Sustainable Future: Assessing the Long-Term Effects of Motor Vehicle Transportation on Climate and Ecology. National Research Council, Washington, D.C.

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