A representative schedule is presented of vehicular operating costs. The differences between which are caused only by changes in vehiclular gross weight, and/or changes in types of trailer combinations. Such representative vehicular cost data later can be related to representative costs for highway facilities with different load-carrying capabilities. The report describes how the different cost factors were adjusted for differences in prices paid for fuel, wages, fringe benefits, depreciation and interest charges, and new vehicles. The data are presented in an extensive series of charts showing the variations in vehicle-mile costs by loaded gross weight for all the 23,384 trailer combinations, all the gasoline engine powered trailer combinations and all the diesel powered combinations using either gasoline or diesel engines. Other charts and tables show how unit costs are affected by body type, type of terrain, average daily travel mileage, average load speed, and other operating variables.