User’s Guide for Quantifying the Effects of Vehicle Mix on Crash Frequency and Crash Severity
Heavy vehicle traffic and vehicle mix have a substantial impact on crash frequency and
severity. The consideration of vehicle mix would improve predictive
methods for crash frequency and severity. Improved methods will result in better use of the limited
funds and resources available for improving the safety of the highway system and supporting
performance-based approaches.
NCHRP Web-Only Document 393: User’s Guide for Quantifying the Effects of Vehicle Mix
on Crash Frequency and Crash Severity,
from TRB's National Cooperative Highway Research Program,
develops and validates a statistically valid predictive methodology to quantify the effect of vehicle
mix on crash frequency and severity for various facility types, and
develops a spreadsheet tool for practitioners to quantify the effect of vehicle mix.
The report is supplemental to
NCHRP Research Report 1103: The Effect of Vehicle Mix on Crash Frequency and Crash Severity.
Supplemental to the document are
three spreadsheet tools and 24 datasets across six facilities (note: tools downloaded before March 11, 2024 should be replaced with these current, updated ones).
This Summary Last Modified On: 3/18/2024