| According to the National Highway Traffic Safety Administration (NHTSA), a total of 35,092 people died in motor vehicle crashes on the U.S. highway system in the year 2015. In order to address this issue, transportation professionals have continued to investigate countermeasures that can improve roadway safety, one of which are High Friction Surface Treatments (HFSTs). HFSTs are pavement resurfacing systems made of materials with exceptional skid resistance. They are usually applied in short sections or spot locations where friction demand is critical (e.g. to target rear-end crashes at intersection approaches, or lane departure crashes along horizontal curves). HFSTs have the potential to be an innovative, sustainable, and cost-effective means of improving roadway safety because they utilize and maximize the existing infrastructure.;Since the early 2000s, there has been an increase in state HFST installation projects throughout the United States. This research seeks to review the performance of HFSTs from a safety and economic perspective through an analysis of HFST installation projects in the state of Pennsylvania. Using data provided by the Pennsylvania Department of Transportation (PennDOT), it analyzes the extent of their effectiveness in reducing crash rates and crash severity through a before-after and benefit-cost study of 122 sites. The results of two these investigations indicated that HFST was successfully able to reduce crashes, reduce crash severity, and provide a positive return on investment almost equally in a variety of environments. One alignment, however, that stood out in terms high safety benefit were for horizontal curves with a radius less than 300 feet.;Further statistical analysis along with the American Association of State Highway Transportation Officials (AASHTO) Highway Safety Manual (HSM) was used to develop crash modification factors (CMFs) and safety performance function (SPF) calibration factors to help quantify the average number of crashes per year and better estimate the crash reduction and that can be expected at a particular location by installing HFSTs, as a function of various geometric and traffic features. This investigation showed the lowest crash modification factors for urban intersections and rural two-lane segments. The goal of this study is to enable transportation professionals to maximize their investment and to better anticipate the safety benefits of a HFST project prior to programming and construction. |
