When does Congress take on the real work of governing?

That was a central question surrounding the debate last week as the Senate and House went back and forth on different approaches to keeping the nation’s Highway Trust Fund solvent.

The final answer? Next May.

Congress on Thursday agreed to a funding patch that will transfer about $11 billion to the Highway Trust Fund, the main account that pays for improvements to the nation’s highway system. That’s enough to keep the fund paying for road work in all 50 states until May of next year.

That gives Congress about 10 months to find a permanent solution to a perpetual highway funding problem in the U.S. Or it gives Congress 10 more months until it puts together its next crisis-driven, patchwork plan.

The $11 billion transfer that will rescue the highway fund is just the latest multibillion-dollar transfer to the Highway Trust Fund. Since 2008, the fund has needed more than $50 billion in one-time patches.

We’re glad to see that funds for highway work will continue flowing uninterrupted, especially at the height of Maine’s construction season. Had Congress not come up with a patch, the U.S. Department of Transportation would have started scaling back payments to the states on Aug. 1.

For Maine, the loss for August would have been $27 million to $29 million, according to the state Department of Transportation. That’s about 17 percent of the approximately $165 million Maine receives each year from the Highway Trust Fund.

Road improvements throughout the state — from major paving jobs to bridge construction — would have continued in August and September, but the state would have had to turn to other funding sources, such as bond funds authorized by voters, sooner than it had planned. By Oct. 1, the state would have had to start reducing or delaying payments to contractors for work already performed, and the Department of Transportation’s ability to start up new projects listed in its three-year work plan would have been in doubt, said DOT spokesman Ted Talbot.

Clearly, the immediate fix was needed. But just as clear is the need for Congress to arrive at a more enduring solution to the nation’s highway funding dilemma.

The root of the problem is a federal gas tax that has remained at 18.4 cents per gallon of gasoline (and 24.4 cents per gallon of diesel) since 1993. If the gasoline tax had kept pace with inflation, it would be 30 cents per gallon today.

To add to that revenue source’s inflation-induced funding incapacity, the amount of money raised by the gas tax has been on the decline in recent years as people drive less — due to a weak economy and a tendency among many younger Americans not to drive — and they drive more fuel-efficient cars.

Raising the federal fuel tax and indexing it to inflation — just as the federal government indexes income tax brackets and Social Security payments — is a first step to ensuring an adequate funding stream for highway improvements. But the fuel tax won’t remain an effective way to collect revenue forever — especially as fuel efficiency rises and gradually fewer cars depend on gasoline.

If Congress takes on the real work of governing after the temporary funding dries up next May, it would also explore alternative funding mechanisms — such as a per-mile tax on vehicles or increased tolls — for the long term.

That would be a lot to expect from a Congress not accustomed to carrying out the people’s business. But the nation is in dire need of such deliberate problem-solving.

On the state level, Maine is facing a smaller version of the same problem. The state stopped indexing its fuel tax to inflation in 2011, and state Highway Fund revenues — which account for 42 percent of state transportation funding — have declined in recent years.

Our hopes aren’t high, but wouldn’t it be great if, next May, Congress solved the highway funding problem and set an example for states such as Maine?