7.5.6 Safety Analysis

There may be instances where a corridor does not have congestion-related issues, but safety is an issue due to roadway geometry, incomplete traffic control, faulty pavement markings, low quality signage, or other reasons. Rural segments of corridors are often more inclined to have safety-related issues than congestion-related issues.
Similar to traffic analysis, safety analysis is performed for two conditions, existing and future. The purpose of safety analysis for existing conditions is to identify existing safety issues and develop safety countermeasures for those issues. Existing conditions safety analysis methods include:
  • Historical crash data analysis;
    • This includes crash types, contributing factors, crash rates,
    • crash severities, crash heat maps, and other crash data-related analysis to help Traffic and Safety Analysis Procedures Manual | 2024 7-18 understand safety-related issues on the corridor.
  • PSI Analysis; and
  • Identifying countermeasures
The purpose of the future safety conditions analysis is to consider safety implications of alternatives that have been developed. Future conditions analysis can be conducted in a variety of methods, some of which are listed below.
  • Relative comparison of CMFs; and
  • HSM Part C Predictive Method
More information regarding how to perform existing and future safety analysis is presented in
Chapter 5
 and
Chapter 6
.