Abstract
A great deal of overseas research has been conducted on the inter- relationship between the construction, maintenance and utilisation costa of a roading system. The results have been used to produce model for vehicle operating costs relative to road characteristics, including roughness and road deterioration rates. If economic evaluation methods are to have credence, it is essential that New Zealand research on actual vehicle operating costs over a wide range of road characteristics is given priority and suitable methods for predicting pavement performance are developed for surface sealed roads.