Uncle Sam collects the federal gas tax and deposits the proceeds into an account called the Highway Trust Fund (HTF). This revenue pays for the construction and upkeep of the nation’s transportation system. Over-spending by Congress and the effect of recent high gasoline prices are creating a perfect storm that by the end of the year will have created a multibillion-dollar trust fund deficit.

Like clockwork, Congress has responded by throwing money at the problem. There are proposals in front of both the House and Senate that will transfer $8 billion from the general Treasury to the HTF. Proponents argue that this step is justified because way back in 1998, a provision in a previous transportation bill transferred $8 billion from the HTF to the Treasury. That money has long been spent, however, so that justification is pretty weak. The real problem here, however, is that the fix proposed by Congress does nothing to fix the problems with the trust fund itself. The gas tax alone will not be sufficient in the years ahead to maintain our transportation infrastructure at a safe and efficient level and feed the seemingly endless congressional appetite for highway pork. Four-dollar a gallon gas has reduced the amount of driving American’s are doing by tens of billions of miles, resulting in a seismic drop in revenue into the HTF. The recent decline in gas prices won’t be enough to save us though. When the most recent transportation bill was signed into law in 2005, with gas at a mere $2.32 per gallon, it was very clear then that Congress had promised more in the bill than the trust fund could pay for.

There is little political will to increase revenue by raising the federal 18.4 cents per gallon gas tax. We must agree with Secretary of Transportation Mary Peters who recently said, “We can’t afford to continue pinning our transportation network’s future to the gas tax.” Nor can we afford to pin our hopes on a large infusion of cash from the Treasury. The solution is going to require that Congress gets creative.

When Congress gets back after the election, it will be time to begin debating the next transportation bill. Keeping the HTF functioning is going to take a combination of revenue raisers and spending reductions. Increasing the ability of states to toll on federal highways and incentives to toll on state and local roads—the most direct kind of user fee—is one way to raise revenues. Getting rid of the billions in earmarks and changing the federal match for new construction projects (while incentivizing smaller, targeted projects that reduce congestion and increase safety) are great ways to reduce spending.

The Highway Trust Fund, and the transportation system it supports, is far too valuable a resource to allow it to dry up. Congress is excellent at spending money; now it needs to get serious about fixing a trust fund running on empty.