Ton-mile tax is one method for a government to tax road usage in order to generate funding for road construction and maintenance. This tax is levied based on the actual weight being carried for each trip and the number of miles travelled. The taxes are set based on the weight of the truck, and for larger trucks, the number of axles is also taken into account. It attempts to allocate the costs based upon the wear and tear that the vehicle puts on the road since a heavier vehicle will cause a road to deteriorate faster. Proponents argue that such a tax gives drivers incentives to drive vehicles that are lighter or spread the weight over more axles. The administrative costs of these taxes appear to be quite high, and some states that previously used ton-mile taxes have repealed them.
However, Oregon's weight-mile tax rates are based on the average weight carried by a vehicle of each class, so it is only necessary to keep track of mileage rather than mileage and weight. Since truckers typically keep track of mileage anyway, this method greatly reduces the administrative costs. Truckers are claim that such costs must be borne by consumers.
