Tax per gallon, or per mile?

As the Nissan Leaf does not use any gasoline, its drivers do not pay for highway maintenance. (Credit: Josh Miller/CNET)

A report by the Congressional Budget Office (CBO), requested by Senate Budget Committee Chairman Kent Conrad (D-N.D.), looks at the feasibility of taxing drivers based on miles driven. To implement the tax, the CBO found that technology exists to seamlessly record and transmit mileage.

Conrad requested the report to explore means of raising money to fund a $556 billion budget request by the Obama administration to maintain highways. Currently, funds are raised from an 18.4-cent-per-gallon federal tax on gasoline and a 24.4-cent-per-gallon federal tax on diesel. Conrad suggested an alternate per-mile tax due to lower revenues from the gas tax as vehicles become more efficient.

While saying per-mile metering devices were feasible, the report fell short of estimating the cost of implementing metering devices. It said that, while it would be less expensive to require manufacturers to install metering devices as original equipment, the phase-in would take many years.

Implementing a per mile tax would face many similar hurdles. If every car in the nation could not be equipped with a factory-installed or aftermarket metering device all at the same time, the tax would need to allow some drivers to pay the per mile tax, and others to continue to pay the per-gallon tax.

Both Oregon and Washington are already considering some means of taxing cars that use little or no gas. Previously, Oregon considered a per-mile tax. Both states are currently looking into a road tax aimed specifically at plug-in vehicles.

By CNET