In an effort to improve safety on rural arterials, Snohomish County installed an innovative technology to enhance road surface traction. High friction surface treatments (HFST) are a thin layer of specially engineered, high friction aggregates that produce long lasting skid resistance.
In 2016, Washington State Department of Transportation’s (WSDOT) Innovative Safety Program awarded Snohomish County $1.3 million to apply HFST to 17 sections of rural roads throughout the unincorporated areas of the county. Prior to treatment with HFST, the county did a pre-treatment friction test on the road surface of 3 different roadway sections. After placement of the treatment, Snohomish County performed a series of post-treatment friction tests on all 17 sections. The results showed a significant increase of street surface traction after treatment.
From 2011 to 2015, a total of 9,597 automobile collisions were reported within Snohomish County. Of these crashes, 33 percent involved injuries or fatalities. Snohomish County Public Works performed an in-depth review of the data and identified a list of locations where the use of HFST might reduce the number of crashes. HFST may help in reducing collisions by enhancing the ability of the road surface to provide pavement friction to vehicles while braking or performing cornering maneuvers.
The 17 areas where HFST was applied included sections of Marine Drive, Pioneer Highway, 100 Street NE, Storm Lake Road, 171 Avenue SE, Marsh Road, Jordan Road, Old Snohomish Monroe Road and Old Owen Rd.