Influence of pavement surface macrotexture on pavement skid resistance

Abstract

Pavement skid resistance is one of determining road features that contributes to traffic safety. Several influencing factors govern the skid resistance, amongst which the pavement surface texture is the one that could be designed and controlled by the pavement engineers. Pavement surface texture is classified into four categories, where microtexture and macrotexture level affect the pavement skid resistance. Microtexture contributes to skid resistance at low traffic speed, while macrotexture governs skid resistance at high speed. Macrotexture is a result of asphalt mixture properties, mostly the aggregate gradation, maximum aggregate size, binder and air voids content. Macrotexture is usually measured using different volumetric or optical devices, and the measuring results are expressed as texture depth or profile depth values. Several studies showed that macrotexture level can be correlated to pavement skid resistance performance. Previously conducted small-scale case study performed on road network in City of Rijeka analyzed the influence of pavement surface renewal treatment on macrotexture values increase and its influence on skid resistance values. In this paper, an analysis of measured macrotexture and skid resistance values is shown for a greater set of data. The measurements were conducted on selected highway section in Croatia, using laser profilometer for macrotexture determination and surface friction trailer for skid resistance determination. Both pavement surface performance indicators – Mean profile depth (MPD) for the macrotexture and longitudinal friction coefficient (LFC) for the skid resistance were measured before and after the renewal treatment in order to determine the influence of the renewal treatment on the surface performance improvement. The measured values were then correlated, showing that skid resistance is connected to the level of pavement surface macrotexture.