Robert St. Onge, secretary of the state Department of Transportation, has the same message for the Legislature as his predecessor: Without billions of dollars in new revenues for roads over the next 20 years, his job will be “to manage the decline of the state highway system.”

Former DOT head Buck Limehouse also sounded the alarm about the state’s declining roads and bridges during his tenure. And now St. Onge has taken up the cause.

He told a Senate Committee Jan 16 that the DOT needs $29.3 billion over the next two decades to make the road system “good” again. And, like Limehouse, St Onge thinks that increasing the gasoline tax or higher fees for driver’s licenses and auto registrations are the most sensible ways to raise money for infrastructure. Those are among the proposals a Transportation Department study committee would like lawmakers to consider.

Unfortunately, Gov. Nikki Haley and leaders in both houses of the Legislature are resistant to raising gasoline taxes or other auto-related fees. Haley said that although she expects money for roads to increase by about $77 million in the coming fiscal year, she would not approve a gas tax increase.

But $77 million doesn’t come close to the estimated $1.5 billion a year the state would need just to keep pace with repairs and ongoing construction. Hundreds of miles of roads and many of the state’s bridges already are in disrepair, creating safety concerns statewide. And the condition of our infrastructure can only grow worse as the state continues to fall behind in maintenance and repairs.

South Carolina has the fourth-largest state-maintained highway system in the nation, a system that is made up of 41,460 miles and 8,357 bridges. Yet the state also has the fourth-lowest gasoline tax in the nation.

That tax was last raised in 1987. While raising the gas tax alone would not provide all the money needed for roads, it would significantly boost revenues for that purpose.

Lawmakers should regard the gas tax as a user fee paid by those who put wear and tear on our highway system. But it also would be paid by out-of-state drivers who use the roads and fuel up as they criss-cross the state.

In short, it is the fairest way to pay for road construction and maintenance.

South Carolina needs to follow the example of other states, raising its gas tax to a reasonable level, then allowing it to fluctuate with the average price of a gallon of gasoline. That way, the state could keep pace with its road needs without having to periodically raise the gas tax.

Failing to provide the money for roads and bridges is false economy. Safe, well maintained roads are essential to the state’s economy, especially tourism, its largest industry.

And while motorists might pay a few pennies less per gallon at the pump than residents of other states, they are likely to pay more for damage and wear to their vehicles. Worse, they can have no confidence that the roads they are traveling are safe.

State lawmakers now have heard the same warnings from two successive DOT heads. It’s time they listened.