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FHWA Highway Safety Programs

Synthesis of Methods for Estimating Pedestrian and Bicyclist Exposure to Risk at Areawide Levels and on Specific Transportation Facilities

fhwasa17014.pdf (2.29 MB)

January 2017
Publication No. FHWA-SA-17-041

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This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of this document.

The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official policy of the U.S. Department of Transportation. This report does not constitute a standard, specification, or regulation.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Technical Report Documentation Page

1. Report No.
2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
Synthesis of Methods for Estimating Pedestrian and Bicyclist Exposure to Risk at Areawide Levels and on Specific Transportation Facilities
5. Report Date
January 2017
6. Performing Organization Code
7. Author(s)
Shawn Turner, Ipek Sener, Michael Martin, Subasish Das, Eva Shipp, Robert Hampshire, Kay Fitzpatrick, Lisa Molnar, Ravi Wijesundera, Mike Colety, Stewart Robinson
8. Performing Organization Report No.
9. Performing Organization Name and Address
Texas A&M Transportation Institute, College Station, TX 77843-3135
University of Michigan Transportation Research Institute
Kimley-Horn and Associates, Inc.
10. Work Unit No. (TRAIS)
11. Contract or Grant No.
DFTH6116D00004, TTI Task Order #2
12. Sponsoring Agency Name and Address
U.S. Department of Transportation
Federal Highway Administration
Office of Safety
1200 New Jersey Ave SE
Washington, DC 20590
13. Type of Report and Period Covered
Task 3 Synthesis:
Aug. 2016 - Jan. 2017
14. Sponsoring Agency Code
15. Supplementary Notes
16. Abstract

This report summarizes the variety of methods used to estimate and evaluate exposure to risk in pedestrian and bicyclist safety analyses. In the literature, the most common definition of risk was a measure of the probability of a crash to occur given exposure to potential crash events. There was also consensus on a theoretical definition of exposure as a measure of the number of potential opportunities for a crash to occur. However, there is wide divergence on operational definitions of exposure, and an even wider range of exposure measures being used in practice. Geographic scale is a critical element in most exposure analyses, and most analyses reviewed could be grouped into one of four scales: 1) regional (e.g., city, county, state); 2) network (e.g., traffic analysis zone, Census tract, Census block group); 3) road segment; and, 4) point (e.g., mid-block or intersection street crossing). This report summarizes numerous examples of exposure estimation methods at these different geographic scales, and discusses the data sources and analytic methods used to estimate exposure in these different geographic scales. Other pedestrian and bicyclist risk factors besides exposure also are cataloged.

17. Key Words
Pedestrian and bicyclist exposure to risk, exposure scale, risk factors, pedestrian and bicyclist counts, demand estimation
18. Distribution Statement
No restrictions.
19. Security Classif.
(of this report)

20. Security Classif.
(of this page)

21. No. of Pages
22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized.

List of Abbreviations

  • ACS American Community Survey
  • BAC Blood Alcohol Concentration
  • FHWA Federal Highway Administration
  • GIS geographic information system
  • GPS Global Positioning System
  • HCM Highway Capacity Manual
  • HSIP Highway Safety Improvement Program
  • ITE Institute of Transportation Engineers
  • MoPeD Model of Pedestrian Demand
  • MPO metropolitan planning organization
  • NACTO National Association of City Transportation Officials
  • NBPD National Bicycle and Pedestrian Documentation Project
  • NCHRP National Cooperative Highway Research Program
  • NCIPC National Center for Injury Prevention and Control
  • NCSA National Center for Statistics and Analysis
  • NDS Naturalistic Driving Study
  • NHTS National Household Travel Survey
  • NHTSA National Highway Traffic Safety Administration
  • NTPP Nonmotorized Transportation Pilot Program
  • ScRAM Scalable Risk Assessment Methodology
  • SHRP 2 Strategic Highway Research Program 2
  • TAZ traffic analysis zone
  • TMG Traffic Monitoring Guide
  • TTI Texas A&M Transportation Institute
  • TxDOT Texas Department of Transportation
  • UMTRI University of Michigan Transportation Research Institute
  • USDOT United States Department of Transportation
  • VMT vehicle miles of travel