It is argued that the typically delayed change to the worse for subsequent users of a road, initiated by a passing heavy vehicle, is a function of the damage caused by the strains and stresses from that heavy vehicle and the subsequent maintenance actions taken by the road agency. Therefore, marginal costs caused by the heavy vehicle cannot be assessed without investigating the maintenance strategies used by the road agency. We investigate the functional relationships given in the Swedish National Road Administration's Effektsamband 2000 documents with respect to inherent marginal costs of wear and tear. It is argued in some detail, why the models utilized in the Effektsamband 2000 documents should not be used for deriving these marginal costs.