Gov. Nikki Haley has landed on a good use for most of the $163 million in additional revenue forecast for the coming fiscal year: Use it to repair the state’s crumbling roads and bridges.

Unfortunately, her proposal only scratches the surface of a deeply rooted problem. The state needs $29 billion over the next 20 years to get its 41,000 miles of roads and 8,000 bridges in good condition, according to a yearlong study by the Transportation Infrastructure Task Force, a group created by the state Transportation Commission.

That’s more than $1 billion a year for the next two decades. Haley’s proposal barely qualifies as a start.

And even as she preaches about the dire need to upgrade the state’s road system for the sake of our economic future, she insists that the state’s gasoline tax stay where it has been since 1987 – a flat 16.75 cents a gallon.

The numbers just don’t add up, and it’s time lawmakers and the governor recognize it and act on it.

House Speaker Bobby Harrell comes closer to the mark with a bill to use $100 million in annual sales tax revenue collected on vehicles to pay for roadwork.

A House subcommittee amended the bill to use 80 percent for road repair, with the remaining 20 percent staying in the general fund to pay for K-12 education.

If lawmakers really want to have an impact with this source of money, they could eliminate the $300 cap on vehicle sales taxes.

We’re talking about robbing Peter to pay Paul with this proposal, but at least it would set up a dedicated stream of revenue from a related source: vehicle sales.

Haley says she applauds this idea, but also wants to use the expected extra money for road repairs. That’s fine, but much more can be done.

South Carolina has the fourth-largest state-maintained road system in the country and one of the lowest fuel taxes.

The gas tax brings in about $450 million a year.

If the tax had been adjusted for inflation since 1987, it would now be 33 cents per gallon.

Lawmakers could look at a gasoline tax that would be a percentage of the gasoline sale.

That would help combat a problem with the flat tax – no matter how high gasoline prices go, the tax stays the same.

With higher gas prices and more efficient vehicles, less gasoline is pumped.

A percentage tax would allow the state to collect more money as the price goes up and would help offset lower use.