Abstract
This report documents the results of a research project to support CDOT in the area of Safety Performance Function (SPF) development. The project involved collecting data and developing SPFs for ramp-freeway merge zones categorized as isolated, non-isolated and weave. For each of these three categories, data for the period 2007 to 2011 were collected at sites selected to ensure statewide geographical representation and coverage of the range of traffic volume and other variables in each category. The development of SPFs for the three categories of ramp-freeway merge zones was successful. Separate SPFs were developed for Total, fatal+injury (FI) and Property Damage Only (PDO) crashes. (Author/publisher)