How to Get Trucks to Pay their Fair Share of Road Maintenance

Hampton Roads weigh station. Photo credit:

Hampton Roads weigh station. Photo credit:

by James A. Bacon

Once we embrace the logic of basing road-maintenance expenditures on Return on Investment analysis, as I discussed yesterday, we should address a related matter: the fact that some vehicles cause far more damage to roads than others. In an equitable and economically efficient world, vehicles would pay for damage in proportion to which they cause it. As a practical matter, that would mean getting trucks to pay a greater share of taxes than they do now.

The wear and tear on a road caused by a vehicle increases geometrically in proportion to the vehicle’s weight per axle. Thus, virtually all pavement damage is caused by trucks and buses, contend Clifford Winston and Fred Mannering in a recent article in the Economics of Transportation journal. The rear axle of a typical 13-ton trailer causes more than 1,000 times the damage of a car. (Governing magazine quotes road planners as saying that a heavy truck causes close to 10,000 times the damage of a car.) Heavy trucks likewise cause disproportionate stress to bridges.

Trucks in Virginia, like other states, are taxed far more heavily than cars. But they still are under-taxed in proportion to the damage they cause and the maintenance liabilities they generate. Getting trucks to pay their fair share is difficult because an influential trucking lobby blocks any redistribution of the tax load. But there may be a way to package tax reform to make it palatable to the trucking industry: by making it a win-win proposition.

States do a couple of things that truckers don’t like: (1) they impose weight caps on trucks and tractor-trailers, which limits how much they cargo they can carry, and (2) they require trucks on highways to stop and get weighed, which costs them time.

But what if…. What if Virginia required trucks to pay 100% of the road damage they cause while (1) eliminating weight caps and (2) no longer requiring them to stop at weighing stations, measuring them instead with high-speed “weigh in motion” technologies as they travel down the highway? The first measure would provide trucks more flexibility. They could increase weights (and pay a proportionately higher charge) when the cargo justified it. They could deploy trucks that spread the weight over more axles. They could adjust their routes to minimize travel over bridges for which they incurred high charges. The second measure would save them time in a situation where time was money.

One would think it should be possible to build a coalition of interests — railroads, shippers, motorists — to counter the trucking industry’s lobbying clout. Then make the tax increase easier to swallow by providing tangible inducements such as weigh in motion. It should be possible to budge this powerful lobby into going along.

Update: A correspondent reminds me that the General Assembly tackled the issue of overweight trucks in the 2012 session. It may be settled politically in the sense that the legislature has no intention of returning to it any time soon, but the problem has not been solved. A December 2011 study that laid out a new fee schedule for overweight loads estimated that it would raise an extra $4.7 million a year — a drop in the bucket.