RALEIGH --  State officials are considering charging drivers by the mile. The concept would replace the gas tax, and those behind the idea say it would generate almost $500 million in annual state revenue.

Will Wilkins, executive director of a National Transportation Research Group called TRIP, said, "It's a matter of the public being aware that if they spend a little, they may save more in the long run."

The Department of Transportation is emphasizing that state leaders are just reviewing options to raise more revenues to cover escalating costs for road construction, repairs, and expansion with a growing population.