The National Academies

NCHRP 22-47 [Active]

Incorporating Driver Behavior and Characteristics into Safety Prediction Methods

  Project Data
Funds: $600,000
Staff Responsibility: William C. Rogers
Research Agency: University of North Carolina at Chapel Hill
Principal Investigator: Raghavan Srinivasan
Effective Date: 9/1/2020
Completion Date: 3/1/2023
Comments: Research underway



Driver behavior and characteristics represent some of the most influential contributing factors to traffic crashes.  However, current safety analysis tools primarily incorporate infrastructure-related factors affecting crashes.  This creates a problem for those considering safety applications since some of the most important factors are not included.  This could lead to safety solutions that may not work as well as intended.  In the Highway Safety Manual (HSM), the measures of driver characteristics are divided into several categories such as attention and information processing, vision, perception-reaction time, and speed choice.  Police officers usually report driver characteristics such as gender, age, speeding, blood alcohol content, seat belt use, and distracted driving.  While several studies have evaluated the impact of these factors on crash severity, there is a need to incorporate these factors in widely implemented crash prediction methods to achieve a better picture of the true potential effects on crash severity and frequency for decisions in planning, design, and operations. 

Research is needed to develop a methodology to incorporate a wide variety of factors related to driver behavior and characteristics into crash prediction methods to allow for a more comprehensive assessment of existing and expected safety performance, for use in design and operational decision-making, and incorporation into the HSM and other safety tools and guidelines.




The objective of this research is to develop a methodology to incorporate driver characteristics and behavior into safety prediction methods that can be used to estimate the expected crash frequency and severity related to infrastructure features for use in planning, design, and operational decisions.  The predictive method(s) shall be suitable for inclusion as part of the HSM as a tool to quantify safety performance across modes.


Note: During the methodology development process, the contractor shall plan and provide for pilot testing by multiple agencies as approved by NCHRP.




The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.


Note: The proposer shall collaborate with the activities of AASHTO and TRB on the HSM as well as with activities related to FHWA’s Interactive Highway Safety Design Model (IHSDM) and the upcoming third edition of the Human Factors Guide. 


The research plan should delineate the tasks required to develop a methodology necessary to accomplish the research objective.  At a minimum, the research should address the following:  

  •  Review the literature that has evaluated or estimated the impacts of driver characteristics and behavior to identify variables that have been found to contribute measurably to the number and severity of motor vehicle crashes;
  • Identify and assess the data needs, including available data sources, the quality of the data obtained, an outline of the data collection and compilation plan, and evaluate the ease of access and use of these data by traffic safety practitioners;
  • Identify and assess the adequacy of selected variables that can be incorporated into the evaluation of safety performance;
  • Apply the guiding principles established for HSM development and available guidance concerning measures of safety, research protocols, and other potentially applicable topics;
  •  Evaluate alternative modeling approaches and identify the modeling approach most suited to achieving the research objective;
  •  Propose a work plan for developing and validating the predictive methodology to estimate crash frequency and severity;
  • Develop a validated predictive methodology that can be used to estimate crash frequency and severity that is suitable for inclusion in the HSM;
  • Develop a spreadsheet tool to implement the application of the new methodology;
  • Prepare input data sets for the research, the fused and integrated research data sets, data dictionaries, and steps in the data fusion and integration process as they are developed;
  • Recommend considerations for developing calibration factors or functions;
  • Develop draft text, sample problems, and commentary to incorporate into the HSM.  The commentary shall include assumptions and limitations of appropriate use; and
  • Develop proposed documentation and guidance to provide practitioners with an enhanced understanding of the effects of driver behavior and characteristics on measurable safety performance to inform planning, design, and operations decisions.  

The work plan must be divided into phases as determined by the proposer.  Each phase must be organized by task, with each task described in detail.


A kick-off teleconference of the research team and NCHRP shall be scheduled within 1 month of the contract’s execution.


Note: NCHRP will host all web and conference calls with the research team and the project oversight panel.


Phase I will consist of information gathering, data assessment and review, and refinement of the work plan for subsequent phases.  Phase I will culminate in the submission of an interim report describing work completed in the Phase I tasks.  An in-person meeting will be held with NCHRP to discuss the interim report.  No work shall be performed on Phase II without NCHRP approval. The project schedule shall include 1 month for NCHRP review and approval of the interim report.


Phase II shall consist of the NCHRP-approved Phase II tasks and the development of the final deliverables.


The final deliverables shall include (1) the methodology to incorporate driver characteristics and behavior into safety prediction methods that can be used to estimate the expected crash frequency and severity related to infrastructure features for use in planning, design, and operational decisions; (2) a final report documenting the entire project and incorporating all other specified deliverable products of the research and an appendix to the final report which shall include electronic files of all data used in the project and the results of the analyses conducted with the data; (3) a scalable, accessible, changeable electronic presentation of the methodology that can be tailored for specific audiences, and a train-the-trainer toolkit; (4) recommendations for additional research; and (5) a stand-alone technical memorandum titled, “Implementation of Research Findings and Products” (see Special Note B for additional information).

Note: Following receipt of the draft final deliverables, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverables.




A. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the brochure, "Information and Instructions for Preparing Proposals" (http://onlinepubs.trb.org/onlinepubs/crp/docs/ProposalPrep.pdf). Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower-tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower-tier subaward and subcontract in excess of $25,000.


B. The NCHRP is a practical, applied research program that produces implementable products addressing problems faced by transportation practitioners and managers. The benefits of NCHRP research are realized only when the results are implemented in state DOTs and other agencies. Implementation of the research product must be considered throughout the process, from problem statement development to research contract and beyond completion of the research. Item 4(c), "Anticipated Research Results," must include the following: (a) the "product" expected from the research, (b) the audience or "market" for this product, (c) a realistic assessment of impediments to successful implementation, and (d) the institutions and individuals who might take leadership in deploying the research product. The project panel will develop and maintain an implementation plan throughout the life of the project. The research team will be expected to provide input to an implementation team consisting of panel members, AASHTO committee members, the NCHRP Implementation Coordinator, and others in order to meet the goals of NCHRP Active Implementation: Moving Research into Practice, available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP_ActiveImplementation.pdf.


C. Item 5 in the proposal, "Qualifications of the Research Team," must include a section labeled "Disclosure." Information relevant to the NCHRP's need to ensure objectivity and to be aware of possible sources of significant financial or organizational conflict of interest in conducting the research must be presented in this section of the proposal. For example, under certain conditions, ownership of the proposing agency, other organizational relationships, or proprietary rights and interests could be perceived as jeopardizing an objective approach to the research effort, and proposers are asked to disclose any such circumstances and to explain how they will be accounted for in this study. If there are no issues related to objectivity, this should be stated. 

D. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively very knowledgeable in the problem area. Selection of an agency is made by the project panel considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) how the proposer approaches inclusion and diversity in the composition of their team and research approach, including participation by certified Disadvantaged Business Enterprises; and, if relevant, (6) the adequacy of the facilities.

Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 12 of the proposal. 

E. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academies of Sciences, Engineering, and Medicine. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academies of Sciences, Engineering, and Medicine. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.


F. Resumes for proposed key staff should be limited to 3 pages for each.  The research approach shall be limited to 15 pages.  This does not include the detailed budget or the detailed schedule.


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