The Scientific Argument for Dramatically Increasing Road Taxes on Trucks

Posted On 10th February 2017

Back in the 1960s, highway engineers developed a rule of thumb called the “Fourth Power Rule”, which I learned about in the following article:

The rule says that if you double the weight on an axle, your vehicle does sixteen times the damage to the road.  So, it seems rational that trucks should pay proportionately much more in highway usage taxes than they currently do, since the weights they pull are much more damaging to the roads than cars are.

Another article (link below) on Bloomberg brings up several more interesting points. It points out that at least half the cost of a road is maintenance.  It also points out that infrastructure is not in as bad shape as it was ten years ago, though congestion is worse. However, that is not a federal problem.  It is a state, local, or regional issue.

States seem to look for “free money” from our federal government to finance these projects, which seems crazy.  If steep increases in usage taxes will rationally charge users according to the maintenance bills their weights generate per the Fourth Power Rule, and those funds can go to the states/regions that build out the infrastructure, which seems to be federal budget neutral way to handle infrastructure improvements.  If this can be done transparently and simply with whoever driving heavier weights on the roadways paying a higher rate per pound, that seems a rational way to handle this cost.

I would urge our friends in the trucking industry, including the Transportation Intermediaries Association (TIA), to not oppose such road tax proposals. If such taxes are consistently levied on ALL trucks, we will stay on the same playing field and such an increased usage tax, if correctly applied and easy to pay, is in the public interest.

Tom M.