Oregon is testing a new system that would tax drivers by the mile to pay for transportation projects.
The system, which is known as MyOreGo, will be the first so-called "vehicle miles traveled" program in the nation. The Oregon Department of Transportation says the program will be voluntary and has promised drivers' personal information will be protected.
Drivers who join the program will be charged 1.5 cents per mile for trips that take place on Oregon roads. Participants will be given the option of using a GPS to record their miles or using a non-GPS option that will track usage based on the mileage counters of cars.
In return for participating, the drivers will be offered a tax credit reimbursing them for the 31-cent-per-gallon Oregon gas tax.
Participation in the program will initially be limited to 5,000 cars.
The idea of switching to a mileage-based tax system to bolster sagging transportation funding has been proposed before at the national level, but was quickly dismissed amid critics' complaints that monitoring the number of miles drivers traveled would violate their privacy.
Transportation advocates say something must be done to shore up the dwindling revenue stream from the federal gas tax, which is set at 18.4 cents per gallon.
The tax has not been increased since 1993 and has struggled to keep pace with construction costs, as cars have become more fuel efficient.
The federal government typically spends about $50 billion per year on transportation projects, but the gas tax only brings in about $34 billion each year at its current rate.
Federal budget analysts have estimated it will take about $100 billion, in addition to the gas tax revenue, to pass a transportation bill that lasts at least five years, which is the traditional length of multi-year infrastructure funding packages that have been passed by previous Congresses.
Lawmakers have balked at both the idea of asking drivers to pay more at the pump and at taxing them by the mile to help pay for transportation projects, so they settled on a two-month extension of a transportation funding bill that was scheduled to expire on Sunday.