SAN FRANCISCO (CBS) — California is moving closer to charging drivers for every mile they drive.

The state says it needs more money for road repairs, and the gas tax just isn’t bringing in enough revenue.

The state recently road-tested a mileage monitoring plan.

The California Road Charge Pilot Program is billed as a way for the state to move from its longstanding pump tax to a system where drivers pay based on their mileage.

But it’s not just a question of money, it’s also a question of fairness.

State Senator Scott Wiener and others are saying that when it comes to road taxes, it’s time to start looking at charging you by the mile rather than by the gallon.

“If you own an older vehicle that is fueled by gas, you’re paying gas tax to maintain the roads. Someone who has an electric vehicle or a dramatically more fuel-efficient vehicle is paying much less than you are. But they are still using the roads,” Wiener said.

“People are going to use less and less gas in the long run,” according to Wiener.

And less gas means less gas tax and less money for road repair.

“We want to make sure that all cars are paying to maintain the roads,” Wiener said.

Read the rest of the story on CBSSF.com.