Economics of Pavement Condition , Axle load , and Vehicle Operating Costs

T total cost of moving goods by truck over a highway system involves two basic compon~nts: -the public costs associated with construction and maintenance of the road network, and the privately financed costs of acquiring, operating, and maintaining a fleet of trucks. These publicly and privately financed costs are directly linked in many ways. For instance, the more trucks there are, the more wear and tear to the highways; the greater the loads permitted on each axle, the higher the road construct ion and maintenance costs; the worse the condition of the highway system, the greater the vehicle operating costs. To ensure that these two components of the transportation system—the vehicles and the roads—are compatible with each other and to attempt to keep the overall private and public expenditures on the total system to a minimum, it is necessary to establish design and maintenance standards for the roads and limits on the weights and dimensions of trucks. The maximum length, height, and width of vehicles on the system influence the geometric design standards for the highways, whereas vehicle weight limits control the design of pavement strength and of structures.