U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Scale and Scope of Safety Assessment Methods in the Project Development Process
Long Description
Predicted Average Crash Frequency for Multiple-Vehicle Crash types is calculated as:
- Predicted average Multiple-Vehicle crash frequency of a C-D road segment with base conditions, one lane, and fatal and injury severity equals the product of 0.5 and the exponential of -2.997 plus the product of 0.524 and the natural log of the product of 0.001 and 9800 plus the product of 0.0699 and 0.001 and 9800. (HSM Equation 19-22, p. 19-31 with urban one-lane C-D road segment FI crash severity constants from HSM Table 19-7,p. 19-32.)
- Predicted average Multiple-Vehicle crash frequency of a C-D road segment with base conditions, one lane, and fatal and injury severity equals 0.164 crashes per year. (Approximately 0.164 FI multiple-vehicle crashes)
- Predicted average Multiple-Vehicle crash frequency of a C-D road segment with base conditions, one lane, and property damage only equals the product of 0.5 and the exponential of -3.311 plus the product of 1.256 and the natural log of the product of 0.001 and 9800 plus the product of 0 and 0.001 and 9800. (HSM Equation 19-22, p. 19-31 with urban one-lane C-D road segment PDO crash severity constants from HSM Table 19-7, p. 19-32.)
- Predicted average Multiple-Vehicle crash frequency of a C-D road segment with base conditions, one lane, and property damage only equals 0.321 crashes per year. (Approximately 0.321 PDO multiple-vehicle crashes)
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Page last modified on November 18, 2016