Incorporating Network-Level Friction Data Into KYTC’s Pavement Resurfacing Prioritization Process

The Kentucky Transportation Cabinet (KYTC) currently prioritizes pavement resurfacing projects based on pavement condition ratings, Laser Crack Measurement System (LCMS) data, and District-level input. Although pavement friction is a consideration, KYTC has not had friction data available for the entire state-maintained road network. In 2020, the Cabinet retained a consultant to collect continuous pavement friction data along the state’s road network using a Sideway-force Coefficient Routine Investigation Machine (SCRIM), and Kentucky is now one of a few states that maintains a continuous pavement friction management program. This report discusses efforts to integrate data on road friction into the Enhanced Pavement Prioritization Index (EPPI), which KYTC will soon begin using to prioritize resurfacing projects. Kentucky Transportation Center (KTC) researchers worked in conjunction with the Cabinet’s Operations and Pavement Management Branch in the Division of Maintenance to develop a methodology that accounts for friction demand. Using previously developed estimates of crashes saved, researchers computed the expected number of crashes saved over a five-year period for pavement sections if their Mean SCRIM Coefficient (MSC) value were increased to 45. Six methods of assigning MSC values to individual pavement sections in EPPI calculations based on crashes saved per mile were evaluated. Only one method examined — Natural Log — both aligns with how KYTC assigns weights and does not rely on arbitrary assignments. Researchers are now working with the Cabinet’s Operations and Pavement Management Branch to develop an SQL-based implementation tool that can be used to conduct cost analyses based on crashes saved and cost differences across the Cabinet’s 12 districts.