NCHRP 17-20 [Completed]
Technical Support for the AASHTO Task Force on Roadside Safety (TFRS)
| Project Data
Background: In 1993, following the publication of NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features, the Federal Highway Administration adopted the recommended procedures by referral as the national standard through the rule-making process. At the time, the full impact of this action was not understood by the states. The cost of such mandates became clear after the September 1994 FHWA memo mandated large-scale changes in the application of common guardrail end treatments. To meet the mandate, states found themselves needing to replace numerous roadside devices that seemed to be performing adequately. Many states found the costs of meeting this mandate to be tens of millions of dollars. This unexpected expense and the time required to assess the states' current barrier hardware against the 350 requirements delayed the development and acceptance of new hardware. Only limited efforts were focused on developing new non-proprietary hardware, and although a few new proprietary hardware designs did reach the market, there was little competition in the market to keep the prices low.
The NCHRP, following a long history of being responsible for developing and maintaining recommendations for crashworthiness evaluations, initiated Project 22-14 in 1996. The research of Project 22-14 will involve reviewing NCHRP Report 350 and identifying areas where updates are needed to address changing conditions (e.g., greater numbers of light trucks in the fleet). The results of this effort are likely to illustrate a need to develop a successor to NCHRP Report 350 over the next 5 years.
AASHTO organized a "Special Task Force for 350 Implementation" to address the impacts of the federal mandates on the state DOTs. This task force was successful in clarifying the federal mandates and in reaching agreement on what could and could not be achieved by October 1, 1998. One outcome of these task force efforts was the recommendation that AASHTO play a stronger role in future development, approval, and maintenance of the procedures through the Task Force on Roadside Safety (TFRS). The TFRS represented the most appropriate body to take on this responsibility, but because very few state DOT employees were involved in the development or crash testing of new hardware, they needed technical assistance to effectively comply with the federal mandates. Furthermore, the time required to meet these new responsibilities made it difficult for the committee volunteers to complete other assignments, such as the updating of the Roadside Design Guide. Therefore, some means of support was necessary, particularly over the initial years of the handling this responsibility.
Objective: The objective of this research is to provide the resources necessary for TFRS to undertake the critical efforts associated with the development, approval, and maintenance of procedures for the crashworthiness evaluation of roadside features.
Tasks: Efforts to support the Task Force on Roadside Safety may include the following: (1) Formulation of a plan for periodic or continual updating of the procedures for the evaluation of highway safety features in conjunction with TRB and other interested parties. Once a plan has been made a part of the TFRS responsibility, there will be the need to undertake the analyses, reviews, and evaluations necessary to monitor trends, identify new hardware types, update crash testing procedures, analyze the potential impacts, and solicit feedback from affected parties. (2) Crash testing of roadside hardware to validate the effectiveness and/or impacts of new crash testing procedures to address changing conditions or improved safety criteria. (3) Support efforts to update the Roadside Design Guide and other materials intended to aid DOT staff in making rational and cost-effective decisions relative to the application of devices. (4) Evaluation of the impacts of proposed changes to testing requirements to assess the short- and long-term impacts, particularly where safety benefits may be marginal. This might involve detailed analyses of crash reports, field studies, or cost-benefit analyses. (5) Identification of critical data elements and development of an information resource, to include at least an oversight of the management of information related to roadside safety in a central repository (e.g., a website). The information included in the central resource might involve crash reports, crash testing results, in-service evaluations, and simulation results. (6) Coordination with other committees and agencies relative to crash test requirements. For example, it is important that requirements for post-embedment be consistent with other standards. The TFRS might be called upon to support the FHWA in decisions relative to the acceptance of crash test results for particular hardware items. (7) Development of research needs and identification of priorities for them. (8) Undertaking of other analyses as needed to promote effective roadside safety policy and programs.
It is critical that the TFRS make appropriate decisions relative to roadside safety on behalf of AASHTO. Since the issues are complex and the primary means of getting answers highly technical or costly, it is necessary that the task force have resources to seek answers. Furthermore, since only two states are equipped to undertake crash testing and no state has the capability to conduct finite-element simulations, it is necessary that access to these services in a timely manner be provided. It is also appropriate that a group like TFRS play an integral role in maintaining data and information on the crashworthiness of typical roadside hardware. Therefore, it will be necessary to formulate a plan for information gathering, maintenance, and distribution.
Status: Tasks 1through 4 have been completed. Task 5 was cancelled.
Task 1, Publication of the Year 2000 AASHTO Roadside Design Guide
Consultant: Trauner Consulting Services
Principal Investigator: Michael Radbill
Effective Date: November 15, 2000
Completed: November 30, 2001
Funds Allocated: $35,000
In the past, updates of the American Association of State Highway Transportation Officials (AASHTO) Roadside Design Guide (RDG) have been accomplished through the volunteer efforts of the AASHTO Task Force on Roadside Safety. The task force met in September 1999 to discuss preliminary chapter drafts and has made many decisions regarding the intended revisions. Subsequently, revised chapter drafts have been prepared. Despite these efforts toward a Year 2000 revision to the RDG, the task force believes that without assistance, publication will be delayed.
The objective of this task was to provide assistance to the Task Force on Roadside Safety and the AASHTO Publications staff in publishing a year 2000 edition of the RDG.
Status: This task has been completed and the final deliverables have been submitted to AASHTO for inclusion in the 2002 Roadside Design Guide.
Task 2 Identification of Specific References Used in Developing Criteria and Recommendations in the Roadside Design Guide
Consultant: Nystrom Consulting
Principal Investigator: Kimberly Nystrom
Effective Date: July 8, 2002
Completed: March 31, 2004
Funds Allocated: $55,900
The objective of this study was to identify original research studies and other source material used in the Roadside Design Guide.
Status: This task has been completed. A list of research studies and other source material has been developed for each chapter of the Roadside Design Guide. A CD containing the resource materials has been delivered to the Task Force on Roadside Safety.
Task 3 Flair Rates for W-Beam Guardrail
Consultant: University of Nebraska-Lincoln
Principal Investigator: John Reed
Effective Date: October 10, 2003
Completed: January 24, 2005
Funds Allocated: $50,000
The objective of this study was to evaluate the effect of increased flare rates on impact performance and identify optimal flare rates that minimize total crash costs.
Status: This task has been completed and the final report has been delivered to the Technical Committee for Roadside Safety.
Task 4 Crash Testing of a Secure Mailbox
Consultant: George Washington University
Principal Investigator: Dr. Azim Eskandarian
Effective Date: May 16, 2002
Completed: June 3, 2003
Funds Allocated: $25,000
The objective of this study is to conduct a full scale crash test of a secure mailbox mounted on a steel post. The FHWA is developing finite element models of mailboxes. The crash test will be used to validate the models.
Status: This task has been completed and the final report has been submitted to the Task Force.
Task 5 Full Scale Crash Test to Evaluate the Safety performance of Secure Mailboxes
Consultant: George Washington University
Principal Investigator: Dr. Nabih Bedewi and Dr. Abdullatif Zaouk
Effective Date: February 4, 2004
Completion Date: February 3, 2005
Funds Allocated: $25,000
The objective of this study is to conduct a full scale crash test of a secure mailbox mounted on a wood post. The finite element analysis of these cases has indicated the potential for occupant compartment intrusion.
Status: Contract cancelled.