Operating expenses of the canadian heavy-vehicle fleet exceed several times the expenditures on the public road system, but sound aids that recognize the importance of user costs in road investment decisions are lacing. A state-of-the-art model of user costs was developed after a study in brazil by the world bank. The current versionof the highway design and maintenance standards model, hdm-iii, is evaluated for relevance to the canadian heavy-vehicle operating conditions, and the results of preliminary calibrations for five typicalvehicles are presented. The model is relevant to studying road infrastructure issues. It is also easy to operate and calibrate, but thecost-roughness slope and the effect of road texture, a roadworks decision variable in canada, remain to be validated. The model will become more useful once the effects of congested traffic conditions onoperating speeds are incorporated. Maintenance and depreciation costs need closer examination because they are interrelated and complicated by the inclusion of factory warranty costs in the purchase price. Maintenance cost formulas themselves need reevaluation because they were developed for a low labor-cost environment. If the present hdm-iii "adjusted utilization method" is retained, it should be modified to account for the fact that time savings on a haul do not necessarily translate into additional trips. Relationships for cargo delay and damage due to road conditions also need improvement. This paper appears in transportation research record no. 1262, Planning, management and economic analysis 1990.
Samenvatting