There has been increased discussion over the state Department of Transportation’s need for more funding, in the wake of a report citing nearly a $30 billion gap between revenues and the price tag for essential projects over the next 20 years. And while talk is cheap, there’s been some progress on plans to provide new funding.

The latest was House approval of a proposal from House Speaker Bobby Harrell to commit sales taxes on vehicles to the highway fund. Rep. Harrell’s idea is that revenue derived from motor vehicles should be committed to highways.

It’s a logical idea.

At latest estimate, the proposal would generate $80 million for the DOT, and would be phased in over the next two years. It would make a dent in the DOT’s shortfall, but hardly enough.

Meanwhile, an amendment to raise the long-standing $300 cap on motor vehicles sales tax was defeated. Currently, the purchaser of a new luxury car pays the same income tax as the buyer of a mid-range used vehicle. It hardly seems fair.

And a proposal to actually raise the gas tax was defeated in the House as well.

Too bad. As Rep. B.R. Skelton, R-Pickens, points out in a column on today’s Commentary page, the gas tax serves as a user fee for those who drive our roads. And 30 to 40 percent of it is paid by out-of-state motorists.

Rep. Skelton tried to improve the prospects for his proposal by including a temporary income-tax rebate to in-state motorists. That would have ensured that a greater share of the burden would fall on out-of-state motorists and truckers.

Rep. Skelton is a former economics professor at Clemson University. But it doesn’t take a Ph.D. to recognize that the half-measures toward highway funding from the speaker and Gov. Nikki Haley aren’t going to get the job done.

The state gas tax is one of the lowest in the nation and hasn’t been raised since 1987. No wonder South Carolina’s roads keep getting worse.

State Transportation Secretary Robert St. Onge has said that without a major infusion of revenue he can only preside over the road system’s gradual decline.

Clearly, the issue has the attention of our elected officials. And motorists have to be generally aware of the problem, given the worsening condition of state roads.

State lawmakers should get serious on a gas tax hike this year, even if they signed Grover Norquist’s no-tax pledge.

They can explain to Mr. Norquist that the gas tax is really a user fee.

And they’d be right.