SPR 13-454 Dev. and Calibration of Safety Performance Functions

The objective of this research is to review Highway Safety Manual methodologies and as needed, develop state-specific SPFs that can be used with appropriate CMFs to compare safety consequences among various alternatives and locations, and identify cost-effective countermeasures and strategies. A review of the HSM will be made to determine which of the SPFs will most likely be developed based on Kentucky-specific data. Selected SPFs will be targeted for further analysis and an assessment of required data for development of state-specific SPFs will be made. Data will be accumulated and regression analysis will be performed to develop the SPFs. Comparisons will be made between those SPFs presented in the HSM (based on national data or a sample of data from various states) and those SPFs developed based on Kentucky-specific data. For SPFs that cannot be developed based on Kentucky data, a default process will develop state-specific calibration factors for application to the SPFs. It is anticipated that continued analysis will be required to go beyond the initial development of SPFs in order to evaluate and update Kentucky SPFs as necessary, and to assess and compare the impact of state-specific default values as input to the SPFs.