The federal gas tax, set at 18.4 cents per gallon, hasn't been raised since 1993 despite the intervening inflation.
The tax also has taken a hit as cars have become more efficient. Getting more miles per gallon means vehicles are able to pay proportionately less in taxes as they put wear and tear on roadways.
A tax related to vehicle miles traveled (VMT) would be the fairest way to fund highways, especially with the growth of electric vehicles, but such proposals have bogged down over fears the system might allow government to spy on motorists.
And while the government may have earned those fears through other surveillance efforts, the fact is that a VMT system need not be vulnerable to tracking cars.
Another idea that should get serious consideration is allowing states to toll existing interstate highways to raise revenue.
Unfortunately, those and other ideas to change the system in a way that raises revenue fairly would take time to craft and refine time the highway fund doesn't have.
The simplest and most effective way of dealing with the issue is for Congress to approve the proposal from Sens. Chris Murphy, D-Conn., and Bob Corker, R-Tenn., and raise the gas tax so critical infrastructure work can continue across the nation.
Good infrastructure is key to our prosperity, and Congress should ensure that it doesn't continue to deteriorate.