Novel Macro- and Microtexture Indicators for Pavement Friction by Using High-Resolution Three-Dimensional Surface Data

It is widely recognized that pavement surface texture is important for pavement friction and roadway safety. Mean profile depth, the primary index used to characterize macrotexture, is a two-dimensional height indicator calculated from a single profile, which is insufficient to represent surface texture, especially for friction studies. This paper explores five categories of three-dimensional (3-D) areal parameters to characterize pavement texture attributes and develops the relationship between pavement friction and the 3-D texture parameters. The newly constructed Long-Term Pavement Performance Specific Pavement Study 10 site in Oklahoma was selected as the test bed. Pavement texture and friction data were collected in parallel at the same predefined locations with a portable ultrahigh-resolution 3-D laser scanner and a dynamic friction tester, respectively. Correlation analyses among the 24 3-D texture parameters were conducted to exclude those that exhibited strong correlations and to remove the potential multicollinearity for regressional friction model development. Multivariate analysis was then performed to develop the relationship between the selected 3-D texture parameters and dynamic friction tester friction data at various testing speeds. Core material volume and peak density were identified as the most influential macro- and microtexture parameters that exhibit fairly good correlation with friction data at high and low speeds in wet conditions. Results indicate the identified 3-D texture parameters provide better alternatives for characterizing pavement surface texture attributes with respect to pavement friction performance.