Engineering Safer Road Surfaces to Help Achieve U.S. Highway Safety Goal

In recent years, there has been a major increase in activities related to improving highway safety in the United States (U.S.). This is emphasized by the publications by the American Association of State Highway and Transportation Officials (AASHTO) of the 2008 Guide for Pavement Friction and the 2010 Highway Safety Manual (first edition), by the NCHRP 500-series reports (Guidance for Implementation of the AASHTO Strategic Highway Safety Plan), and by the updated Federal Highway Administration (FHWA) regulations and guidance regarding the Highway Safety Improvement Program. These and many other recent or ongoing research and technology development activities are beginning to have a positive impact on the nation’s crash fatalities; a number that in 2008 dipped below 40,000 for the first time since 1962. Much emphasis has been placed on improving highway safety from the standpoints of driver behavior (e.g., addressing aggressive, distracted, and impaired driving and the neglected use of seat belts) and roadway design (e.g., geometrics, roadside, and traffic control features). However, an important but often overlooked aspect of the road—the pavement surface—has been shown to be a significant factor in highway safety and thus has become a major area of focus at the FHWA, the National Cooperative Highway Research Program (NCHRP), and many state highway agencies (SHAs). This paper provides a detailed and up-to-date look at how safety is being addressed in the U.S. from the realm of the pavement surface. It presents basic information on the more significant national studies and events involving pavement surface characteristics and their impacts on highway safety. It gives special focus to the topic of pavement friction and texture, describing the traditional approaches and state-of-the-practice for testing and ensuring pavement friction at the network level and discussing the primary shortcomings of those practices. More importantly, it presents the latest efforts to cultivate new and improved methods and technologies for minimizing the effects of friction and texture on highway crashes and the devastating number of fatalities and injuries stemming from those crashes. Such efforts are intended to help FHWA and AASHTO achieve its current highway safety goal of reducing fatalities by half in 20 years.