The purpose of this paper is to estimate the marginal cost for structural repair of road pavement. To this end we use a method that departs from a relation between heavy traffic intensity and the time that elapses between two repavement occasions. This function is estimated using a comprehensive data set, including all repavements on the Swedish National road network since the 1950's. From this relation we derive a deterioration elasticity, i.e. the relative change in the repavement interval in response to a change in the volume of heavy goods vehicles. Together with a unit pavement cost, the deterioration elasticity is used to compute the marginal structural repair cost associated with an additional heavy goods vehicle. We find the deterioration elasticity to be quite low and marginal costs are low accordingly.