GREENVILLE — It is no secret that South Carolina sorely needs additional revenue to upgrade and then maintain its massive system of state-maintained roads and highways. It’s also widely known that this state has not increased its 16.75 cents per gallon gasoline tax since 1987.

Unfortunately, in that environment, Gov. Nikki Haley has proposed an executive budget for the coming fiscal year that still falls well short of state transportation funding needs, and does not include an increase in the gasoline tax. Haley’s budget proposal does include an increase in highway funding, but the $90 million she’s proposing is a drop in the bucket of the $450 million in additional funding needed next year alone to meet the daunting needs that South Carolina faces.

Haley is not alone. Obviously a gasoline tax that has been the same for more than 25 years indicates a Legislature that is too resistant to increasing — or even maintaining — the revenue needed to keep our state’s roads in adequate condition.

No doubt, some of the state’s road problems come from the fact that more than 60 percent of the road miles in South Carolina are state maintained; the national average is less than 20 percent. Yet the state’s gasoline tax is among the nation’s lowest and in the 25 years since it has been at the current level the buying power of that 16-cents-per-gallon tax has diminished to less than 8 cents per gallon when inflation is factored in, according to a recent report by the South Carolina Transportation Infrastructure Task Force.

In addition, the spending power of the gasoline tax is diminishing over time because less tax is being collected as fuel economy improves for vehicles and drivers buy less fuel to travel greater distances.

Haley should promote and lawmakers should pass a gasoline tax increase that helps bridge the state’s huge highway maintenance funding gap.

A gasoline tax increase would not bridge the entire gap, but it is a sensible short-term step to help meet some state highway needs. Consider that up to 40 percent of the gasoline tax is paid by out-of-state residents who are here on vacation or passing through the state, and the impact on state residents already is somewhat mitigated.