Traffic channelisation and pavement deterioration: an investigation of the role of lateral wander on asphalt pavement rutting

Accurate estimation of traffic load plays a crucial role in the economical design of pavements. The cross sectional distribution of the vehicle positions means that the traffic load is spread across the surface of the pavement. Several factors influence the distribution of vehicle positions and hence load. When wheel paths are perfectly aligned with each other, this is termed channelised traffic (or channelisation). This study investigated the impact of channelisation on asphalt pavement rutting. Data was collected on 100 sections of pavement in the city of Portsmouth, United Kingdom including vehicle/wheel positions and rut depths. Regression analysis was conducted to understand how the degree of channelisation influenced the rut depths that the traffic loading had created. The analyses revealed that the degree of channelisation of traffic has a statistically significant contribution to the progress of rutting. In this study, the difference between the maximum and minimum degrees of channelisation observed, related to a seven-fold difference in the rut depth. These findings give further guidance to pavement engineers when designing new pavements and considering the maintenance schedules for existing pavements, as it allows them to better predict the future condition and lifespan of a pavement.