Safe-D: Safety through Disruption

Street Noise Relationship to Vulnerable Road User Safety



Street noise may be a valuable indicator for bicyclist safety, but no studies have evaluated the relationship to date. This study develops a method for evaluating street noise and documented crash rates for roadways in Austin, Texas, and Washington, D.C., in a manner that is replicable by researchers and practitioners. Researchers collect street-level noise in both cities over a range of locations, facility types, and times, and compare these against crash records, normalized by bicycle volumes, and other explanatory variables. Descriptive and inferential statistics of a pilot test suggest a role for street-level road noise impacts to vulnerable road user safety. If this full-scale examination in two cities show consistent results, street-level noise measurement—obtainable by non-experts—may offer time and cost savings relative to other street safety estimation methods for bicyclists. Street noise may be a valuable proxy for safety variables such as motorized vehicle speed, volumes, and proximity to bicyclists, which could result in improvements to facility design and crash modification factors to reduce bicycle crashes.


  • Noise detected on bicycle-mounted smartphones in Austin, Texas and Washington, D.C. evaluated the relationship with crash risk in both cities.
  • Modeling explained 87% of the variation in crash risk in our Washington, DC Capital Area route, after controlling for infrastructure differences and nearby bicycle commute mode shares.
  • Further explorations of street noise are needed to improve further guidance for transportation planning and design.

Final Report

02-027 Final Research Report (PDF)

EWD & T2 Products

Course Presentation (PDF): This presentation includes findings from the project to be used in university-level courses. Project PI Greg Griffin will use these findings in teaching Transportation Planning at the University of Texas at San Antonio in Fall 2019.

Below is a webinar performed by the research team on February 12th, 2020.


Griffin, G. P., Hankey, S., Buehler, R., Dai, B., Le, H., & Simek, C. (2019). Exploring Street Noise and Bicycle Safety: Initial Evidence from Austin, TX and the Washington, DC Capital Area. Proceedings of the Transportation Research Board 98th Annual Meeting, (19–03944). Washington, D.C.: Transportation Research Board. (Published)

Final Dataset

The final dataset for this project is located in the Safe-D Collection on the VTTI Dataverse; DOI: 10.15787/VTT1/5LWJTV

Research Investigators (PI*)

Greg Griffin (TTI/TAMU)*
Steven Hankey (VT)
Ralph Buehler (VT)

Project Information

Start Date: 2017-06-01
End Date: 2018-07-31
Status: Complete
Grant Number: 69A3551747115
Total Funding: $60,234
Source Organization: Safe-D National UTC
Project Number: 02-027

Safe-D Theme Areas

Big Data Analytics

Safe-D Application Areas

Vulnerable Users

More Information

UTC Project Information Form

Sponsor Organization

Office of the Assistant Secretary for Research and Technology
University Transportation Centers Program
Department of Transportation
Washington, DC 20590 United States

Performing Organization

Texas A&M University
Texas A&M Transportation Institute
3135 TAMU
College Station, Texas 77843-3135

Virginia Polytechnic Institute and State University
Virginia Tech Transportation Institute
3500 Transportation Research Plaza
Blacksburg, Virginia 24061