Estimation of the marginal cost of road wear as a basis for charging freight vehicles

The estimated marginal road wear costs, in both short-run marginal cost (SRMC) form and long-run marginal cost (LRMC) form were found to vary across a range of road types and were highly dependent on the pavement/subgrade strength and traffic load. The marginal costs based on the LWC relationship using SAR-km as the independent variable were a constant value until axle group loads were increased significantly above current limits.