As the 15-member commission noted, the “transportation system has deteriorated to such a degree that our safety, economic competitiveness and quality of life are at risk.” The report depicted an astonishing degree of neglect: Real spending on highways has plummeted by 50 percent since the late 1950s, even though vehicle miles traveled have increased considerably in that time; the 18.4-cents-a-gallon federal gas tax has lost one-third of its purchasing power since 1993, the last time it was raised; long-term revenue for the Highway Trust Fund, which helps pay for the country’s roads, will fall an average of $68 billion short of required levels annually. As a result, the commission wrote, there is an “unacceptable and unsustainable investment deficit in our nation’s surface transportation infrastructure.”
The commission argues, that it’s necessary to raise the gas tax in the short term. However, as drivers switch to more fuel-efficient vehicles, the tax will generate insufficient revenue to cover the country’s transportation infrastructure needs. That’s why, after examining numerous alternatives, the commission concluded that a mileage tax was the best way to raise the necessary revenue while reducing the impact drivers have on the environment. In fact, a mileage tax could be much more effective at doing this than the gas tax. A mileage tax could be tailored so that Hummer drivers, for example, paid more per mile than Prius owners. The tax could also be levied at higher rates during rush hour or on congested highways, discouraging people from driving at times when they would spend the longest on the road. It’s no surprise, then, that groups such as the Environmental Defense Fund have praised the proposal.
Most mileage tax proposals call for a tracking device in vehicles that, according to the commission, would “function like the GPS devices that million of Americans have already installed in their cars without worry of privacy loss.” There are potential privacy pitfalls, but, as the commission wrote, “such systems can and should be designed to fully protect travelers’ privacy.” The trackers could be designed so that the government would only receive information about how much a driver owes, not where the driver has traveled. Reassuringly, a successful mileage tax pilot program in Oregon protected drivers’ privacy.
Mileage tax advocates say it’s possible that Congress will include funding to study the proposal, and possibly implement pilot programs, in a major transportation funding bill this year. That would be a good start for a promising idea.