That could complicate efforts by vehicle-mileage-tax supporters such as House Budget Committee member Earl Blumenauer, D-Ore., to prod Congress toward adopting the levy.
His home state is in the process of wrapping up an extensive pilot project in which participating drivers paid 1.6 cents per mile and received a refund of the state gas taxes they paid.
In December, Blumenauer introduced a bill that would mimic that pilot program at a federal level. At the time, he said his legislation would allow officials to evaluate possible methods of collection while protecting the privacy of drivers and administering the program efficiently.
An aide says the congressman plans to introduce a new version of the bill in the next few weeks.
The idea of a VMT tax appears to be gaining at least some modest traction on Capitol Hill.
House Transportation and Infrastructure Chairman Bill Shuster, R-Pa., said late last year that he thinks a mileage tax may be the best way to shore up the Highway Trust Fund.
“There’ll be a shorter-term fix,” he said. “But longer term, vehicle miles traveled may be the only way to stop the decline.”