FLINT, Mich. - The idea of a vehicle-miles-traveled (VMT) tax is being discussed - and tested in states like Oregon and Iowa.

It would be an alternative to the federal gas tax, which is under review by Congress and could lead to a new system for funding highway construction and repairs when the measure comes up for reauthorization in 2014.

The tax would require some way to measure travel, creating the possibility the government will use advanced technology to track car and truck movements.

Under one scenario, automobile manufacturers would be required to install a GPS system - a "black box" - in every vehicle to measure miles traveled. The government would track your vehicle by satellite to calculate the tax.

A large-scale retrofit of existing cars would be necessary. Motorists would pick up the tab for the GPS, which would cost more than $200 each, plus installation.

Another option would require wireless transponders in vehicles to report odometer readings to a central billing office, allowing the VMT tax to be paid when refueling a vehicle.

A major drawback to a VMT tax is that the cost of implementing it would consume a large share of the revenue collected. The U.S. Government Accountability Office estimates that installing GPS systems in 230 million U.S. vehicles could cost up to 33 percent of the revenues generated over a 20-year period.

A VMT tax would disproportionately shift the burden of federal road maintenance onto suburban and rural car owners who drive much farther to and from work, school and for shopping than their urban counterparts.

But it's the "black box" system in particular that's untenable: It would force us to surrender our privacy. Each day, more and more of us are required to tell government agencies more and more about ourselves. Do we really want the government collecting data about our driving habits?

The federal gas tax, which hasn't been raised in 20 years, isn't generating enough money for highway improvements because people are driving less and cars are more fuel-efficient. The upshot is that since 2009, revenue from the tax has fallen short of the minimum needed for transportation improvements, and Congress has had to bail it out four times.

As the average fuel economy of new cars improves, the amount of money available to the highway trust fund may decline as much as 13 percent from 2012 to 2022.

What to do?

Shifting to a VMT system serves neither the interests of good government nor the interests of personal privacy.

To fund highway repairs, an increase in the federal gas tax might be a better option. Increasing taxes may not sound appealing. But the condition of our transportation system will worsen unless we make enough money available for improvements.

A VMT is not the answer. A higher gas tax makes more sense.

No, tracking would be too expensive

Editor's note

Every Monday we offer pro/con pieces from the McClatchy-Tribune News Service to give readers a broad view of issues.

Mark J. Perry is a professor of economics at the Flint campus of the University of Michigan and a scholar at the American Enterprise Institute in Washington.