The objectives of this research were to develop:
- Crash severity and crash type SPFs or distributions or both that can be used in the estimation of the crash type and crash severity likely on the facility types contained or intended for use in the HSM;
- Recommendations of how the research results can be incorporated into the HSM and associated tools, including the development of associated chapters or chapter content in AASHTO standard format for the HSM second edition and recommended procedures for consistent use of crash severity and crash type SPFs or distributions or both; and
- A description of the statistical and practical advantages and disadvantages of the methodology developed in the research and potential barriers to implementation.
This research was to provide a consistent approach for developing and validating crash severity and crash type prediction models to improve the capabilities of the current HSM and associated tools to estimate the safety performance outcomes associated with modifications to the highway and road user environments.