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OCR for page 232
232
Completion Date: December 31, 1979
Funds: $ 154,452
The objective of this project was further refinement and
field evaluation of the two prototype moisture sensors
developed under Projects 21-2 and 21-2~2~. This included
fabrication of the sensors and readout instrumentation,
their installation in the subgrade portions of pavements
in Arizona and Pennsylvania, and evaluation of data col-
lected at the field sites.
Research has been completed, with accomplishment of
the intended tasks. Although neither sensor meets all of
the desired criteria, the research indicates that each has
some potential for practical applicator to the soil moisture
measurement problem. Operational problems encoun-
tered during the field evaluation should be resolved during
the development of production models. A production
model of the dielectric sensor is available from Ecotec
Corp., Needham Heights, Mass.
The essential findings of the study have been published
as NCHRP Research Results Digest 121. The agency
report has been distributed to the Program sponsors and
other interested persons. It will not be published in the
regular NCHRP report series but is available on a loan
basis (see final page of this section for ordering infor-
mation).
AREA 22: VEHICLE BARRIER
SYSTEMS
Project 22-1 FY '69
Concepts for Improved Traffic Barrier Sys-
tems
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Founds:
Walter W. White
Walter W. White
Marvin A. Shulman
October 1, 1970
December 31, 1971
$25,000
The objective of the research was to produce one or
more traffic barrier system designs, described with
sketches and narrative to the degree necessary to convey
understanding, that offer promise of: preventing penetra-
tion by a standard-size U.S. automobile weighing 4,000
to 5,000 lb and impacting at 25° and 65 mph; smoothly
redirecting errant vehicles relatively parallel to traffic
flow; providing a range of controlled dynamic deflections
by varying design parameters; retaining longitudinal con-
tinuity following a collision; permitting adequate visibil-
ity; being capable of quick and easy repair; performing
satisfactorily in various foundation conditions; limiting
decelerations at the center of gravity of the vehicle to 5g
lateral, 10g longitudinal, and a total of 12g when averaged
over any 200-millisec period; having reasonably low first
cost and pleasing appearance; and minimizing vehicle
damage. The design was analyzed and technical infor-
mation was presented to demonstrate the degree of
achievement of the foregoing. Working drawings suitable
for fabrication and installation of a prototype were pre-
pared for each barrier system.
The final report was not published in the NCHRP
report series; however, microfiche of the report may be
purchased (see final page of this section for ordering in-
formation).
Project 22-1A FY '73
Testing and Evaluation of Bridge Rail Con-
cepts
Research Agency: Texas A & M University
Research Foundation
T. J. Hirsch
March 1, 1974
May 30, 1975
$40,000
Principal Invest.:
Elective Date:
Completion Date:
Funds:
The objectives of NCHRP Project 22-1, "Concepts for
Improved Traffic Barrier Systems," were accomplished
by the development of a traffic barrier system that was
analyzed using the Barrier IV computer program. The
results of this analysis indicate that the proposed system
meets the desired criteria.
The objective of Project 22-1A was to evaluate the
prototype of the proposed barrier by full-scale impact
tests.
The accomplishment of this objective included the fol-
lowing tasks:
1. Fabrication and construction of the barrier system
shown in Figure 6 of the final report on Project 22-1
(Pages 148 to 173, NCHRPSummary of Progress Through
1972~.
2. Testing and evaluation of the system under the fol-
lowing impact conditions:
(a) A passenger vehicle impacting the bridge rail at 60
mph and 25°.
(b) A passenger vehicle impacting the bridge rail at 60
mph and 7°.
(c) A passenger vehicle impacting the approach railing-
bridge rail transition at 60 mph and 25°.
Research has been completed, and the essential findings
have been summarized in NCHRP Research Results Di-
gest 81, "Crash Testing and Evaluation of Attenuating
Bridge Railing System."
Microfiche of the agency's final report may be pur-
chased (see final page of this section for ordering infor-
mation).
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233
Project 22-2 FY ,69, FY '72 and FY '73
Traffic Barrier Performance and Design
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Southwest Research Institute
M. E. Bronstad
J. D. Michie
Jan. 1, 1972 Oct. 1, 1973
Sept. 30, 1973 Mar. 31, 1975
$125,000 $80,000
Among the most important of current needs in the area
of vehicle barrier systems is a safer terminal design. The
work of Project 22-2 was structured to emphasize the
systematic experimental development of terminal treat-
ments to fulfill this need. Terminal treatments for a num-
ber of selected guardrail systems were investigated. This
study built on earlier preliminary NCHRP efforts that
are described in NCHRP Reports 118 (1971) and 129
(1972~.
The initial task in Phase I included a review of terminal
concepts previously developed under Project 15-1~2), the
development of several new concepts, and an examination
of concepts developed outside the NCHRP. More than
20 of these concepts have come under consideration. This
work was covered in an interim report. Although the
report will not be published, it is available on a loan basis.
Based on the interim report, the project panel selected
designs and established priorities for full-scale testing of
several terminal systems. The experimental program con-
sisted of some 26 full-scale crash tests. Interest in this
testing was concentrated on a breakaway cable terminal
(BCT) in combination with the W-beam guardrail and
median barrier systems most often used. Ten crash tests
were carried out on the BCT with the flared W-beam
guardrail. The second part of the experimental program,
comprising some 16 tests, was concentrated on the de-
velopment of a crash-cushioning terminal for use with
median barriers. Microfiche of the agency's Phase I report
may be purchased (see final page of this section for or-
dering inflation.
Phase II research has been completed. Task 1 led to
the refinement of BCT designs to provide more safety to
smaller cars and to improve economy relative to the first
cost, maintenance, and repair. Findings from the Phase
II research were reported in NCHRP Research Results
Digest 84 (March 1976~. Microfiche of the agency's final
report on Phase II may also be purchased (see final page
of this section for ordering information).
Subsequently, the Federal Highway Administration
sponsored additional tests on the median barrier BCT.
NCHRP Research Results Digest 102 summarized the
findings of these and previous tests and clarified recom-
mended details for both guardrail and median barrier
terminals with either steel or timber posts.
A separate task of Phase II, funded at $20,000, was
intended to develop uniform barrier testing criteria and
procedures. Research has been completed on this task,
and the final report has been published as: NCHRP Re-
port 153, "Recommended Procedures for Vehicle Crash
Testing of Highway Appurtenances."
Project 22-2~2) FY '73
Multiple Service Level Highway Bridge Rail-
ings Performance and Design Criteria
Research Agency: Southwest Research Institute
Principal Invest.: M. E. Bronstad
Elective Date: August 1, 1976
Completion Date: April 30, 1979
Funds: $195,000
The initial objective of this project was to identify and
document realistic performance criteria and correlated
design criteria for bridge railing systems on roadways
providing various (at least three normal, higher, and
lower) levels of service. The major objective was to de-
velop at least one design based on criteria for the lower
service level and to validate this system using analytical
and full-scale testing methods.
The research included the following tasks:
1. Identify traffic and other parameters for use in de-
fining appropriate categories of roadway service levels.
2. Establish reasonable performance criteria for bridge
railings to be employed in each category.
3. Propose bridge railing design criteria for each cat-
egory.
4. Develop and validate, through analytical simulation
and full-scale testing (in accordance with the relevant
provisions in NCHRP Report 153), at least one lower
service level bridge railing design with first cost and main-
tenance advantages over normal service level systems. The
railing will be designed according to the criteria proposed
in Task 3, to give performance consistent with the criteria
developed in Task 2. Bridge railing designs considered in
this task may include some already in use.
5. Through analytical simulation, evaluate the per-
formance of this railing when struck by a 25,000-lb
(11,340 kg) school-type bus under various impact con-
ditions.
6. Compare the developed bridge railing design with
the present AASHTO static-elastic bridge railing design
requirements.
7. Recommended appropriate modifications to current
bridge railing design practice based on this study.
Research has been completed, and loan copies of the
final reports on Phase I (Tasks 1-3) and Phase II (Tasks
4-7) may be obtained from the NCHRP upon written
request.
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234
Project 22-2(3) Fy '78
Multiple Service Level Highway Bridge Rail-
ings Selection Procedures
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Southwest Research Institute
Maurice E. Bronstad
January 1, 1979
May 31, 1981
$200,000
The concept of multiple service level bridge railings
was developed in NCHRP Project 22-2~2~. The objective
of Project 22-2~3) was to further refine these procedures
to make them more usable and accurate with respect to
the needs of the highway community. Certain improve-
ments had already been indicated from comments re-
ceived on the initial studies.
Several aspects of the Multiple Service Level Approach
(MSLA) were controversial and more comprehensive in-
vestigations were needed. The following steps were carried
out in this program:
1. Perform a sensitivity analysis and refine MSLA pro-
cedures accordingly.
2. Develop bridge railing systems for a number of ser-
vice levels.
3. Determine total costs of bridge railing systems for
a number of service levels.
4. Based on cost, determine number of service levels
needed.
5. Develop an upgrading strategy using MSLA.
6. Prepare a users' manual for practicing engineers.
7. Assess the legal implication of MSLA and make
modifications as indicated.
Research has been completed, and the final report pub-
lished as: NCHRP Report 239, "Multiple-Service-Level
Highway Bridge Railings Selection Procedures." The
findings of a small side study on the breakaway cable
terminal have been published as Research Results Digest
124.
Project 22-2(4) FY ,79
Procedures for Testing Highway Appurte-
nances
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Southwest Research Institute
Jarvis D. Michie
May 1, 1979
February 28, 1981
$30,000
In 1962, the first procedures for full-scale vehicle crash
testing of guardrails were published in Highway Research
Correlation Services Circular 482. The one-page document
delineated vehicle mass, impact speed, and approach an-
gle. Although Circular 482 did bring some some order
to traffic barrier research being performed at several re
search agencies, a number of questions arose that were
not addressed.
Under NCHRP Project 22-2, SwRI addressed these
questions and developed NCHRP Report 153, "Recom-
mended Procedures for Vehicle Crash Testing of Highway
Appurtenances" (1974), which provided testing and re-
search agencies with recommended procedures to vehicle
crash test highway appurtenances. The procedure rep-
resented technical input from more than 70 individuals
and agencies and the results of extensive deliberation of
a special ad hoc panel. It was recognized then that several
parts of the procedures were based on inadequate expe-
rience or research. It was decided, however, to retain
coverage of these areas in order to provide a more com-
plete testing procedure.
These procedures have gained wide acceptance since
their publication in 1974. It was recognized at that time
that periodic updating would be needed, and, in January
1976,TRB Committee A2A04 accepted the responsibility
of maintaining the efficacy of the procedures. Question-
naires were submitted to committee members in late 1976
to ascertain areas of the document that needed revision.
The responses generally fell into two categories: (1) minor
changes that would require expanded discussions of cer-
tain provisions and problem areas and the addition of
more detailed guidelines; and (2) major changes that
would require broadening the scope to include testing
with trucks and buses, reevaluating the criteria for impact
severity, and treating special highway appurtenances such
as construction barriers. The committee agreed to address
the minor changes through special committee action; this
was done, and Transportation Research Circular No. 191
is the product of TRB Committee A2A04. For the major
changes, the committee felt that the task was beyond its
resource and requested TRB/NCHRP to investigate the
possibility of having the work performed under a funded
research contract. Project 22-2~4) was intended to address
these major changes. Its objective was to review, revise,
and expand the scope of Transportation Research Circular
loo. 191 to reflect current technology. This study per-
mitted research on points needing more in-depth analysis
than could be provided by the TRB Committee.
Research has been completed, and the final report has
been published as: NCHRP Report 230, "Recommended
Procedures for Safety Performance Evaluation of High-
way Appurtenances."
Project 22-3 FY,73
Field Evaluation of Vehicle Barrier Systems
Research Agency:
Principal Invest.:
Effective Date:
Completion Date:
Funds:
Calspan Corporation
J. W. Garrett
N. J. DeLeys
January 1, 1974
February 15, 1975
$25,000
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235
The objective of this project was to determine the degree
to which accident data currently being accumulate by
various agencies meet the needs of those concerned with
the effectiveness of vehicle barrier systems and, to the
extent warranted, to recommend new approaches that
may better serve those needs.
Research has been completed, and the essential findings
from the final report have been summarized in NCHRP
Research Results Digest 76, "Field Evaluation of Vehicle
Barrier Systems." Microfiche of the agency's final report
may be purchased (see final page of this section for or-
dering information).
Project 22-3A FY '73
Field Evaluation of Vehicle Barrier Systems
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Arthur L. Elliott
Arthur L. Elliott
July 1, 1974
December 31, 1974
$10,000
The relative in-service performance of most guardrail
systems is unknown. Although over-all performance of
guardrail installations, in general, might be determined
from state and national efforts in accident investigations,
limitations in the data preclude the analysis of specific
guardrail systems in terms of safety and cost. Accordingly,
the relative merits of two or more systems must be eval-
uated on the basis of idealized laboratory experiments
(including full-scale crash tests) and gross accounting pro-
cedures. The use of accident data to evaluate the field
performance of barrier systems would be very desirable.
The use of formal accident reports had been investigated
under NCHRP Project 22-3.
At the same time, Project 22-3A was concerned with
an investigation of a less formal approach to barrier eval-
uation. This approach consisted of personal interviews
with highway agency maintenance, safety, and traffic op-
erations personnel to obtain any data they may have had
and to solicit their subjective opinions on the performance
of various barriers. Five representative states were visited
for this purpose.
Research has been completed, and the essential findings
from the final report have been summarized in NCHRP
Research Results Digest 76, "Field Evaluation of Vehicle
Barrier Systems." Microfiche of the agency's final report
may be purchased (see final page of this section for or-
dering information).
Project 22-4 FY '83
Performance of Longitudinal Traffic Barriers
Research Agency:
Principal Invest.:
Elective Date:
Southwest Research Institute
J. D. Michie, M. E. Bronstad
July 1, 1983
Completion Date: July 15, 1987
Funds: $503,954
Existing crash test performance of longitudinal barrier
systems was reviewed for compliance with NCHRP Re-
port 230. Based on this review a matrix of five guardrail,
two median barrier, and four bridge systems was evalu-
ated with full-scale crash tests for occupant risk with
1,800-lb sedans. The results were evaluated using the
recommended values of NCHRP Report 230 to which all
systems were essentially in compliance.
In addition, evaluation of five guardrail and one median
barrier systems was performed with an 1,800-lb sedan
impacting at 60 mph and a 20-de" angle (test S13 of
NCHRP Report 230~. The purpose of these tests was to
provide further insight into the performance of the barrier
systems. Six insight tests using vans to determine barrier
performance thresholds for this type of vehicle were per-
formed. Seven transition tests were performed as follows:
three guardrail/bridge rail transitions, two guardrail/
guardrail transitions; and two median barrier/median
barrier transitions. Finally, two additional insight tests
were performed. The first was a van impacting a G1 cable
guardrail system mounted at a 24-in. height. The second
test evaluated a blocked-out W-beam system with round
wood posts.
The final report, published as NCHRP Report 289,
includes the crash test results, design drawings for the
systems tested in this research as well as for systems tested
in other studies, and recommended changes to the test
criteria.
Project 22-5 FY '84
Develop Performance Stanclards and
Hardware for Low Service Level
Guardrail Systems
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Southwest Research Institute
L. R. Calcote and K. Hancock
May 1, 1985
January 31, 1989
$200,000
Currently operational guardrail systems have been de-
veloped for 60-mph, 25-degree impacts with 4,500-lb ve-
hicles. The use of design criteria based on this severe test
condition has resulted in relatively expensive installations
(e.g., high-cost terminal anchorage systems). For low ser-
vice level roads, there is a need to determine the conditions
under which less stringent guardrail requirements are
warranted in order to reduce costs while providing safety
performance based on demonstrated need.
The objectives of this project are: (1) to examine the
need for guardrails on low service level roads and develop
performance standards for guardrails, transitions, and ter-
minals and (2) to design, test, and develop low-cost guard-
rail systems based on these performance standards.
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236
This project consists of two phases:
Phase I
Task 1 Review, evaluate, and document available
data in order to establish performance standards for low
service level guardrail systems including transitions and
terminals. Establish and, if necessary, develop general
warranting criteria for use of such systems.
Task 2 Using the performance standards from
Task 1, develop conceptual and preliminary designs with
working drawings of the guardrails, terminals, and tran-
sitions using structural analysis, computer simulation, or
other techniques. Existing hardware and systems in wide-
spread use with demonstrated effective field performance
will be fully considered. Make estimates of initial and
maintenance (life cycle) costs for these guardrail systems.
Task 3 Prepare a letter report on the findings of
Tasks 1 and 2 for review by the NCHRP. This report
will also contain a detailed work plan for Phase II in-
cluding recommendations for further development of the
guardrail systems.
Phase II
Task 4 Test and develop the guardrail systems se-
lected by NCHRP using the approved performance stan-
dards.
Task 5- Prepare a final report including the follow
~ng:
a. Low service guardrail performance standards.
b. Documentation of the design and development of
low service level guardrail systems.
c. Recommended low service level guardrail drawings
and specifications.
d. Estimated life cycle costs of the guardrail systems.
e. General warrants for use of low service level guard-
rail.
Research has been completed, and the draft final report
Is being reviewed.
Project 22-6 FY '85
Roadside Safety Design for Small Vehicles
Research Agency:
Principal Invest.:
Elective Date:
Completion Date:
Funds:
Texas A & M Research Foundation
Dr. Hayes E. Ross, Jr.
June 1, 1985
June 30, 1988
$350,000
Most current roadside safety appurtenances were de-
signed and tested with passenger vehicles ranging from
4,500 down to 2,250 lb. Research is currently in progress
to investigate the performance of hardware and roadside
features with vehicles in the 1,800-lb range. Under some
conditions, barrier impacts become increasingly hazard
ous for smaller vehicles; however, little is known about
the performance of current hardware and roadside safety
features with vehicles smaller than 1,800 lb.
The objectives of this project are (1) to assess the per-
formance of selected existing highway safety appurte-
nances and roadside features with passenger vehicles
below 1,800 lb and (2) to project the limits of vehicle
characteristics that can be safely accommodated through
improvements in current hardware and roadside features.
This research includes the following tasks:
Phase I:
Task 1 Review, evaluate, and document foreign
and domestic information on the performance of safety
appurtenances and roadside features with passenger ve-
hicles weighing 1,800 lb and less.
Task 2 Identify all types of 4-wheel sedans below
1,800 lb that may constitute a significant portion of the
vehicle fleet in the United States within the next 10 years.
For the vehicle types identified, acquire, measure, or,
where necessary, estimate the dynamic properties and
other characteristics required for the computerized sim-
ulation of their reactions with safety hardware and road-
side features.
Task 3 Select specific appurtenances for study in
this project. The following items will be included: a rigid
longitudinal barrier; a flexible longitudinal barrier; a
breakaway support; a base-bending support; an impact
attenuator; and a guardrail terminal.
Task 4 Select specific roadside features for study
to identify performance limits when traversed by small
cars. As a minimum, these features will include slopes,
ditches, and curbs.
Task 5 Using available data from crash tests with
the lightest vehicles tested, calibrate selected existing com-
puter programs for simulation of impact performance,
and use the calibrated programs to simulate occupant-
risk tests for the selected hardware and roadside features
with a 1,500-lb sedan.
Task 6 Prepare an interim report on the findings
of Tasks 1 through 5. This report will contain a detailed
working plan for the remainder of the study.
Phase II
Task 7 Conduct full-scale crash tests using vehicles
in the 1,200 to 1,500-lb range to recalibrate the model
and to demonstrate the validity of the computerized sim-
ulation to be carried out concurrently in Task 8.
Task 8 Using existing simulation models for a va-
riety of appurtenances and roadside features (including
potential improvements), vehicle types (including projec-
tions down to the lowest conceivable weight range), and
crash test conditions, delineate the limiting values of par-
ticular vehicle characteristics for which feasible designs
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237
are capable of providing satisfactory performance ac-
cording to the guidelines in NCHRP Report 230. When
these evaluation criteria are not satisfied, determine the
changes in impact conditions that would be required to
achieve compliance.
Task 9 Identify design modifications to hardware
and roadside features to improve performance for vehicles
at the low end of the weight spectrum. Such modifications
will be supported by computerized simulation.
Task 10. Prepare a final report.
Research has been completed and the final report is
being revised, in preparation of its publication in early
1989.
Project 22-7 FY '89
Update of "Recommended Procedures for
Safety Performance Evaluation of High-
way Appurtenances"
Research Agency:
In developmental stage
Principal Invest.:
Elective Date:
Completion Date:
Funds:
(30 months)
$200,000
The objective of this study is to update the recom-
mended procedures for the safety performance evaluation
of both temporary and permanent highway appurtenances
in such a manner as to reflect advances in technology and
to accommodate current and anticipated roadway and
vehicle characteristics.
This project will consist of two phases to be performed
consecutively, with a review required at the completion
of Phase I on which authorization to proceed with Phase
II will be based.
Phase I
Task 1. Develop a comprehensive list of topics to
be examined in updating the recommended procedures.
This list shall be based on a critical review of past and
on-going research, and input from knowledgeable indi-
viduals involved with and interested in the subject area.
Task 2. Evaluate the relative importance of each of
the topics cited in Task 1 and identify important issues
within each topic.
Task 3. Prepare an interim report documenting the
efforts completed in Tasks 1 and 2. The interim report
shall also include an annotated outline of the final report
and a detailed work plan describing the activities required
in Phase II. Submit the interim report to the NCHRP
Project Panel for review and approval. A meeting between
the research team and the NCHRP Project Panel will be
planned at the completion of Task 3 to discuss the results
of Phase I and the work planned for Phase II. The in
vestigators shall prepare a revised interim report to reflect
the outcome of the meeting and distribute it to the project
panel members.
Phase II
Task 4. Using the information generated in Phase I,
prepare a first draft of the final report and document,
under separate cover, how each of the issues identified
was resolved. The investigators shall also prepare a pro-
posed list of reviewers from the highway community-at-
large for approval by the panel. A second meeting between
the research team and the project panel will be planned
at the completion of Task 4 to discuss the first draft of
the final report, the list of issues identified and how they
were resolved, and the proposed list of reviewers. The
investigators shall prepare a second draft of the final
report to reflect the outcome of the second meeting and
distribute the revised document to the project panel mem-
bers and to the reviewers approved by the project panel
in this task.
Task 5. Evaluate the reviewers' comments and prepare
a brief discussion of the comments and their disposition.
Based on the results of this effort, prepare a third draft
of the final report. A third meeting between the research-
ers and the NCHRP Project Panel will be scheduled at
the completion of Task 5 to discuss the comments received
from the community-at-large, the disposition of those
comments, and the third draft of the final report.
Task 6. A final report shall be prepared based on the
outcome of the third meeting between the researchers and
the NCHRP Project Panel.
Project 22-8 FY '89
Evaluation of Performance Level Selection
Criteria for Bridge Railings
Research Agency:
In developmental stage
Principal Invest.:
Elective Date: (21 months)
Completion Date:
Funds: $200,000
The objectives of this research are (1) to determine the
adequacy and validity of the performance levels and the
performance-level selection procedures contained in the
"Guide Specifications," (2) to estimate the impact of im-
plementing the "Guide Specifications" on state and local
agencies, (3) to recommend appropriate improvements to
the "Guide Specifications," and (4) to evaluate the fea-
sibility of extending the multiple performance-level ap-
proach to all longitudinal barrier systems.
This research shall include four phases. Phase I cor-
responds to the first objective; Phase II, to the second
and third objectives; and Phase III, to the fourth objective.
Phase IV encompasses the preparation of the final report.
Representative terms from entire chapter:
principal invest
