Crash Facts


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Crash Data Analysis

In conventional traffic safety evaluations, the outcome measure is typically the frequency of police-reported crashes, often with separate estimates for different severity levels. However, some treatments may decrease some crash types but increase others. If these crash types are characterized by different average injury severities, then comparing crash frequencies will not provide the user with an accurate picture of treatment effectiveness. Such a scenario led to development of the crash cost estimates by crash geometry described in this report. An example of this scenario can be found in an evaluation of red-light camera (RLC) programs in seven jurisdictions nationwide funded by the FHWA Intelligent Transportation System Joint Program Office and the Office of Safety Research and Development. RLC programs can be expected to decrease angle-type crashes, but to increase rear end crashes. The former is usually more severe than the latter. For that reason, the study not only examined crash frequency by type, but also included crash severity in the analysis by converting each crash to an economic cost, based on unit costs by police-reported crash severity.

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Program Contact

Jeffrey Shaw


What's New

Signalized Intersections: An Informational Guide

South Carolina Case Study: Systematic Intersection Improvements

Stop-Controlled Intersection Safety: Through Route Activated Warning Systems

Roundabouts: An Informational Guide, Second Edition (NCHRP Report 672)

Roundabouts Peer-to-Peer Assistance

How to drive a roundabout (WSDOT)

Modern Roundabouts: A Safer Choice


FHWA's Intersection Resources Library CD-ROM

Roundabouts Technical Summary

Mini-Roundabouts Technical Summary

Access Management in the Vicinity of Intersections Technical Summary

Intersection Safety Case Studies

Intersection Safety Technologies

Presentation: Intersection Safety

Example Intersection Safety Implementation Plan

Intersection Safety Implementation Plan Workshop

Example Data Analysis Package and Straw Man Outline