Putting more fuel-efficient vehicles on the road is universally seen as a good thing, but those gas-sipping hybrids and electric cars crisscrossing Colorado are contributing less and less in terms of the gas tax revenues that pay for badly-needed road and bridge repairs across the state.

Starting in December, state transportation officials will launch a program to test a new way to raise funds that could one day eliminate the need for the state’s 22-cent per gallon gas tax, which hasn’t been adjusted upward in more than two decades: Make motorists pay for every mile they drive.

The Colorado Department of Transportation’s Road Usage Charge Pilot Program will recruit 100 volunteers to track how far they drive and then “pay,” in theory, 1.2 cents per mile for their use of the road. No money will actually change hands, but CDOT hopes to get a sense of how such a system would work in terms of mileage reporting and revenue collection.