Characterizing Rider Safety in Terms of Asphalt Pavement Surface Texture

015055992013Final ReportPDFTech ReportCFIRE 07-08DTRT06-G-0020Asphalt pavementsTexturePavement designFrictionHighway safetyRolling contactTire/pavement noiseMeasuring methodsResearch HubHighwaysPavementsSafety and Human FactorsI23: Properties of Road SurfacesMean profile depthPavement surface texturesFrictionUnited StatesNational Center for Freight and Infrastructure Research and Education (U.S.)Bahia, Hussain U.Rajaei, MozhdehSefidmazgi, Nima RoohiNational Center for Freight and Infrastructure Research and Education (U.S.)United States. Dept. of Transportation. Research and Innovative Technology AdministrationUS Transportation CollectionThe overall goal of pavement design is to meet the intended service life and more importantly to provide a safe riding surface for the traveling public. Therefore, pavements can experience structural failure (i.e. rutting or cracking) or functional failures, where the pavement becomes unsafe from a riders perspective due to a lack of sufficient surface texture (friction). Several countries within the European Union have specifications related to measurement of surface texture already in place to ensure a minimum level of friction. The barrier to implementing similar practices in the United States is in further development of friction measurement and analysis methods. Measuring pavement friction involves specialized equipment with a relatively high initial cost. In addition, many devices require that measurements be made on field pavement sections, incurring further delay in opening new pavement to traffic. Several recent studies have correlated asphalt pavement surface texture with friction using relatively inexpensive, non-intrusive devices. These devices can be used in the laboratory as well as in the field and have shown promise in estimating not only pavement surface texture and friction, but also noise emissions. With further development, these methods will give pavement designers the necessary tools to evaluate asphalt pavement surface texture in terms of pavement friction and promoting the development of new specifications. This project refines and applies these methods to several plant produced mixtures to estimate surface texture and friction. Limits on the mix design parameters most affecting rider safety (friction) will be proposed