Analysis of Wehner-Schulze data and pavement skid resistance of porous asphalt

Pavement skid resistance is closely related to road safety and accident rates; therefore, road agencies need reliable predictive models. This study analyses Wehner-Schulze (WS) data and the skid resistance of porous asphalt pavements to establish relationships between traffic polishing and WS polishing, as well as between field skid resistance and the WS friction after polishing (FAP) parameter. Six motorway branches were investigated by collecting cores from trafficked and untrafficked lanes, including open-graded and semi-porous wearing courses. Historical Sideway Friction Coefficient (SFC) and traffic data were also collected. WS friction measurements were performed on trafficked cores, whereas untrafficked cores underwent WS polishing to evaluate friction decay. The preliminary relationships established allow converting the FAP-WS passes relationship into an SFC-traffic relationship, showing good agreement with historical data. These findings provide a preliminary basis for network-level predictive pavement management models and for estimating skid resistance evolution in the field.