There’s less than a week left for Congress to agree to a highway bill of some sorts. Otherwise, come March 31, all federally funded roadwork will grind to a halt. The U.S. government will no longer collect $93 million per day in gas taxes. And construction workers will get laid off en masse. Chaos.

About to grind to a halt? (David McNew/GETTY IMAGES)

Except, as Politico reports, time is running out, so the House bill is being considered under a suspension of the rules. That means it needs a two-thirds majority to pass. And that’s still far from assured. Meanwhile, Senate Democrats would prefer the House just take up their own two-year highway legislation, though the Senate has quietly conceded that it will consider a short-term extension instead to avoid mass layoffs. But that still leaves the risk that even a short-term bill could get caught in the snags, delays, and cloture motions the Senate is famous for.

Odds are, the House and Senate will figure something out before the March 31 deadline. Ever since the current transportation law expired in 2009, Congress has passed eight short-term extensions to avoid mass layoffs. A ninth wouldn’t be all that far-fetched. And the alternative is too grisly to contemplate.

Even so, the fact that Congress is relying so heavily on short-term extensions imposes real costs on the rest of the country. Those short-term bills make it impossible for states to conduct any sort of rational planning for roads, bridges, and mass transit. “If states don’t have certainty from Congress — meaning a bill that lasts two years or more — then they basically have to guess how much money they have to work with,” said John Horsley, executive director of the American Association of State Highway and Transportation Officials, in an interview earlier this month. “That means they either become conservative in the amount of projects they approve or they simply focus on shorter-term projects and wait on a lot of bigger projects” until they get a better sense of where Congress is headed.

So far, Congress has struggled to come up with long-term bills. One problem is that there’s just not enough gas-tax revenue to play with anymore. The House hasn’t been able to agree on the six-year bill it wants because it’s unclear how to pay for it without raising the gas tax. (And no one in Congress wants to raise the gas tax.) The Senate had to resort to a number of funding gimmicks just to get a two-year bill. None of this will get any easier 90 days from now, when we’re increasingly close to the election.

In the meantime, Congress’s addiction to short-term transportation bills could actually be holding back infrastructure investments around the country. And yet, for the next few months, a short-term bill looks like the most optimistic outcome by far.