Heavy vehicle road wear on sealed unbound granular roads

A sound basis for estimating the load-related road wear due to heavy vehicles on the road network is needed for estimating varying heavy vehicle road user charges on Australia's arterial roads. A network-level equation for estimating the percentage load-related road wear was developed for the typical good-quality uncracked sealed unbound pavements in Australia's sealed arterial road network using a network-level roughness deterioration model based on observational and experimental data. The equation estimated that the percentage load-related road wear varied with changes to the traffic load and pavement strength, and to a much lesser extent an environmental coefficient. This equation gave different estimates of percentage load-related road wear than those based on the HDM-4 roughness deterioration model. The environmental term in the roughness deterioration equation for sealed granular pavements was found to be more appropriate than the environmental term used in the HDM-4 roughness deterioration equation. This outcome implies that the roughness deterioration equation for sealed granular pavements is likely to be more appropriate for predicting Australia's sealed granular pavement deterioration than the HDM-4 roughness deterioration model which was originally based on the deterioration of asphalt-bound pavements.