The National Academies

NCHRP 17-112 [Pending]

Enhancing Crash Modification Factors and Safety Performance Functions for Pedestrian and Bicyclist Countermeasures

  Project Data
Funds: $600,000
Contract Time: 24 months
Staff Responsibility: Richard A. Retting


The AASHTO Highway Safety Manual (HSM), first edition, provides analytic tools and techniques for estimating effects of changes to the roadway environment on motor vehicle crashes, but provides almost no information about effects on pedestrian and bicyclist crash frequency. NCHRP Project 17-84, “Pedestrian and Bicycle Safety Performance Functions for the Highway Safety Manual,” is in the process of developing crash modification factors (CMFs) and safety performance functions (SPFs) for pedestrians and bicyclists in support of a future HSM, second edition (see Special Note L below). However, the safety benefits of many pedestrian and bicycle countermeasures, especially newer  treatments, will still be unknown after completion of NCHRP Project 17-84. Furthermore, established CMFs focused on vehicle-vehicle collisions do not properly account for effects on pedestrian and bicyclist crash outcomes.


The objectives of this research are to (1) develop CMFs and SPFs related to pedestrian and/or bicyclist safety countermeasures and (2) assess pedestrian and/or bicyclist safety outcomes associated with vehicle safety countermeasures.  


The research plan should (1) include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution; (2) address how the proposer intends to satisfy the project objectives; (3) be divided logically into detailed tasks necessary to fulfill the research objectives and include appropriate milestones and interim deliverables; and (4) incorporate opportunities for the project panel to review, comment on, and approve milestone deliverables. 

Accomplishment of the project objectives will require at least the following tasks. 



Task 1. Compile and review findings and recommendations from previous research and countermeasure implementation activities.

Task 2. Identify research priorities to be addressed in Phase II for (1) developing CMFs and SPFs for pedestrian and/or bicyclist safety countermeasures and (2) pedestrian and/or bicyclist safety outcomes associated with vehicle safety countermeasures. Task 2.2 is anticipated to focus on high-priority countermeasures not addressed by NCHRP Research Report 992: Guide to Pedestrian Analysis or NCHRP Web-Only Document 318: Safety Prediction Models for Six-Lane and One-Way Urban and Suburban Arterials. If necessary, propose new methodologies to predict pedestrian and/or bicyclist safety outcomes.

Task 3. Develop a data collection and analysis plan (including surrogate safety measures) for conducting new research in Phase II. The plan should aim to develop CMFs and SPFs, in Phase II, with adequate ratings to support eventual inclusion in the HSM and to support performance-based practical design.

Task 4. Prepare an Interim Report that documents the work completed in Tasks 1 through 3. Update the work proposed for Phase II.



Task 5. Collect data and conduct data analysis according to the approved Interim Report to achieve the research objectives. The findings should consider safety impacts on all vulnerable road users, including those with vision or mobility impairments.

Task 6. Prepare and submit a draft final report.

Task 7. Conduct implementation activities, including (1) prepare draft language for consideration by AASHTO to incorporate the research results into the next update of the HSM (herein called AASHTO Deliverable); (2) participate in a webinar hosted by TRB to share draft findings with a large group of stakeholders, and collect stakeholder feedback for use in finalizing the deliverables; (3) develop outreach materials to support practitioners’ understanding and implementation of the research findings; and (4) propose parameters for conducting pilot tests to apply CMFs and SPFs developed by this project.

Task 8. Final deliverables should include (1) a final research report documenting the entire research effort and findings; (2) AASHTO Deliverable; (3) outreach materials to support practitioners’ understanding and use of the research findings; (4) prioritized recommendations for future research; (5) presentation material; and (6) a technical memorandum on implementation.


STATUS: A response has been received for this RFP.  The project panel will meet to determine next steps.

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