NCHRP 20-7 Proposed Research Needs Statement Standing Committee on Highway Traffic Safety Rudy Malfabon, Nevada, Chair May 16, 2014

TITLE Analysis of Crash Contributing Factors to Determine Appropriate Countermeasures

BACKGROUND / NEEDS STATEMENT To determine how best to address a known or potential safety concern, it is necessary to properly assess the factors contributing to the crashes in order to be able to then determine appropriate countermeasures that can reduce the potential risk. As the field of quantitative safety analysis has developed, many of the procedures using the results of the quantitative analyses have also evolved. The next phase in the growth of this field should support the tasks of analyzing crash data to completely understand or diagnose a particular situation and aid in selecting countermeasures. Development of a document that provides best practices and recommendations on procedures for practitioners to use will further promote use of data- driven, quantitative approaches to consideration of safety in project decisions.

With ever-increasing recognition of the need to more fully assess countermeasures from an engineering, enforcement, emergency medical service, and education perspective, the research proposes guidance for evaluating, analyzing, and diagnosing crash data and potential countermeasures. The research will develop a tool for practitioners to assess the nature of reported crashes, overrepresentation of the contributing circumstances, manner of collision and other factors necessary to determine appropriate countermeasures using more recently developed analysis and decision methods. This includes, but is not limited to, enhancements to the use of collision diagramming and analysis, analytical visualization, gathering supporting documentation and making field based assessments as a means to supplement decision-making within safety programs and projects. The research will should assess how NCHRP Report 600 (2012), Human Factors Guidelines for Road Systems, and other supporting documents related to diagnosing safety concerns are relevant and can be used to assist the practitioner in countermeasure identification and selection. The results of this research will include:

 Case studies which guide safety professionals through recommended analysis procedures for use with the Highway Safety Manual, design exceptions and planning assessments, etc.  Information on best approaches for o Data management and citation during analysis to support repeatability of the analysis, and knowledge management. o Compliance and support of the national open data initiative to promote access to data and tools (refer to www.data.gov for more information). o Perform quality control on datasets and analysis results. o Data linkage to support diagnostics (linkage of crash, roadway, traffic operation, asset management, and other datasets). o Selecting appropriate graphics for diagnostics and reporting. For example, appropriate graph types for representing particular information, usability from a visual perspective, accessibility requirements, and information processing (human factors). o The use of geographical information systems (GIS) for diagnostics and reporting.  Highlight and demonstrate specific statistical analysis necessary to support consistency and reliability of results.

This research will be summarized and provided to the greater highway safety community, the TRB Highway Safety Performance Committee and other related TRB Committees, AASHTO Standing Committee on Highway Traffic Safety and AASHTO Highway Safety Manual Task Force for consideration and dissemination to practitioners for use with safety assessments. This research also provides a valuable supplement to work completed under NCHRP 501: Integrated Safety Management Process, the AASHTO Highway Safety Manual, AASHTO SafetyAnalyst and road safety audits. This effort is directly linked to the AASHTO SCOHTS Strategic Plan Part 6: Management: Improving Information and Decision Support Systems, and the Towards Zero Deaths: a National Strategy on Highway Safety.

RESEARCH OBJECTIVE The objective of this research would be to assess the state of the practice, make recommendations on methods and procedures to complete diagnostic assessments of crashes and the project and program level, and to show appropriate cases studies to complete this activity.

WORK TASKS Tasks anticipated in this project include the following:  Review of related data-driven best practices within the highway safety field and emerging approaches in areas such as public health and big data analytics.  Develop a report that describes recommended methods and procedures, as well as case studies using these procedures.

URGENCY Numerous discussions have occurred on the necessity of providing safety professionals with the necessary tools to adequately performing their tasks of reducing fatal and serious crashes on our transportation systems. A key to meeting this need is being able to diagnosis the contributing circumstances, types of crashes, etc., sufficiently so that projects and programs selected as part of addressing crash concerns will return on investment. This research also provides an essential educational tool that will increase knowledge and ability in completing this difficult task. With the availability of new tools and procedures to assess safety performance this research is timely and urgent. Detailed discussions regarding the need for this research have occurred within AASHTO Safety Management Subcommittee, Task Group for Technical Safety Publication Oversight and Outreach, TRB Highway Safety Performance Committee, and FHWA. There is limited information on diagnostic assessment, or analysis of contributing factors, and the use within safety management and supporting activities that incorporates scientific methods and procedures.

FUNDING REQUESTED AND TIME REQUIRED It is estimated that this research will take 12 months to complete and will require $100,000.

CONTACT PERSON Priscilla Tobias, Illinois DOT Chair AASHTO Subcommittee on Safety Management-Task Group on Technical Safety Publication Oversight and Outreach [email protected] (217) 524-8127

John Milton, Washington State DOT Chair TRB Highway Safety Performance Committee [email protected] (360) 704-6363