Case Study: High Friction Surfacing Treatment (HFST) Crash Reduction Program, Kentucky USA
The annual National Roadway Safety Awards recognises ground-breaking projects that significantly reduce crashes on the US road network. One of the 2013 winners in the Infrastructure Improvements category was the High Friction Surfacing Treatment Program in Kentucky.
Kentucky’s rural, often mountainous terrain can present a challenge to many drivers, and the Kentucky Transportation Cabinet (KYTC) recognized that it needed to apply improved safety treatments on horizontal curves throughout the State to reduce the number of roadway departure or run-off road crashes experienced statewide.
KYTC reviewed a variety of low-cost safety options for reducing roadway departure crashes in both wet and dry weather conditions. After thorough consideration, the KYTC conducted an initial pilot program to improve skid resistance with a high friction surfacing treatment (HFST), a compound comprising a two-part, highly modified epoxy resin binder and a specially graded, high-friction bauxite aggregate.
Under this pilot program, Interstate Road Management, Inc. applied the HFST at 26 locations statewide. After implementation, KYTC measured the friction numbers and found that they had increased dramatically. With the increase in friction came a reduction in skid-related roadway departure crashes and fatalities on treated roadways, a nearly 69 percent decrease.
As a result, KYTC launched a three-year statewide HFST program at over 75 locations in 2010 to improve pavement friction and reduce roadway departure crashes on horizontal curves. HFST was applied at specific sites where skidding crashes resulted in fatalities, serious injuries, and property damage. Each site was linked to crash data collected and plotted by KYTC to ensure appropriate placement of the HFST installation.
A simple before/after comparison shows that when compared with previous 3-year crash data, wet-weather roadway departure crashes dropped from 357 to 33 at sites where HFST has been applied. Similarly, dry-weather roadway departure crashes have also seen a sharp decline, from 126 to 28.