MISSOULA, Mont. -

Tuesday the U.S. House passed an almost $11 billion bill to keep the Federal Highway Trust Fund solvent. It's only a short-term fix, though.

The trust fund is predicted to run out of money by the end of August if Congress doesn't act soon. It pays for construction, maintenance and operation of roads and infrastructure like bridges.

We found out the money comes from a gasoline tax of 18.4 cents per gallon and a diesel tax of 24.4 cents per gallon. The problem is those taxes haven't changed since 1993.

Ideas to fix the problem range from increasing the gas tax, to adding toll roads or taxing drivers based on the miles they drive.

If the fund runs dry, the U.S. Department of Transportation would have to cut federal reimbursements to states as soon as next month.

In Montana, about 60 percent of the money for highway projects comes from federal funding, which is a lot higher than many other states.

That means road construction projects the state has planned for next year might be cut or delayed and could mean a loss of up to 10,000 road construction jobs, plus funding for local transit systems could also be cut.

After looking into the National Bridge Inventory Database, NBC Montana found several bridges that are structurally deficient in western Montana.

There are nine bridges in Missoula that fit the category of structurally deficient, with three in the city limits. Those bridges are the Higgins Avenue Bridge, Russell Street Bridge and Madison Street Bridge.

"It makes me a little nervous, yeah," said Loy Koch.

Koch is just one resident who frequently uses the Higgins bridge. Hearing that it's structurally unsound was a little worrisome and other residents shared the same opinion.

"Of course it's something that concerns you. It's not the first thought that comes across you, but these things do happen and if they're ignored, they don't go away," said Michael Albans.

Keeping the bridges in good condition is a big priority, but Montana relies heavily on federal funding to pay for upkeep. A lapse in the Highway Trust Fund could put a halt to future bridge projects.

Right now, the Russell Street Bridge is in the design phase. Funding is in place for that phase, but could potentially not move forward to construction without the Highway Trust Fund.

A Missoula bridge study shows that both the Higgins Avenue and Madison Street Bridges need major rehabilitation.

"Fixing the concrete riding surface, probably replacing the riding surface. It would entail trying to do whatever works necessary on the steel beams and then anything that was necessary on the support columns and such that are on that. The other thing that would be included in that is looking at can we increase the bicycle-pedestrian facility that's on it," said bridge engineer Kent Barnes.

The Montana Department of Transportation inspects about half of the bridges each year.

"Those elements are in a state where we need to pay extra attention to them. They are probably at a point where some repair is appropriate," explained Barnes.

To see a list of bridges in our area that are structurally deficient click here.