A pilot program to test taxing motorists by the mile launching July 1 could prove to be the solution to building and maintaining roads even as gasoline consumption drops. The program has its pros and cons, but some alternative to the traditional per-gallon gas tax must be found.

Once again, Oregon finds itself in the forefront of a new approach. Under the test program, up to 5,000 volunteers will have their vehicles equipped with a device that records the miles they drive. The volunteers can choose a GPS device that also records where they drive or a device without GPS.

The volunteers will agree to pay 1.5 cents per mile driven on public roads within the state instead of the per-gallon gas tax paid at the pump. If they buy gas, the state will compensate them for taxes paid at the pump, or bill them it they don't purchase fuel. 

The tricky part of this test is figuring out how to not charge drivers for miles traveled out of state or on private property without intruding on privacy by monitoring where people go. Eventually, as more states and eventually the federal government shift away from the gas tax, tracking where people drive shouldn't be necessary. Until then, privacy should be protected; the state should erase any GPS data collected.

Electric-vehicle owners complain they're being singled out, and they're right, to a point. But they do need to pay their fair share. It's in everyone's interest to maintain the roads we all use.