The last-minute stopgap solution passed by Congress Thursday night to temporarily prop up the Highway Trust Fund — yes, the solution built out of budget gimmicks — provides funding through the end of next May. The timing of that deadline had been a point of contention over the last few weeks. Many Democrats, and several Republicans in the Senate, wanted a fix that would last only through late December on the thinking that Congress might find the will to forge a six-year bill in the window between the midterm elections and the end of this congressional session.

Resetting the clock to next May instead means that Washington will pick this fight back up at a time when Republicans may control both the House and the Senate. The shifting balance of power on the Hill will no doubt have implications for what happens next spring. But so could another variable that's gotten less attention: the price of gas.

May usually marks the beginning of peak summer gas prices:

US Regular All Formulations Gas Price, via FRED

For reasons that we've discussed before, people are sensitive to fluctuations in gas prices in ways that we're not when it comes to milk or bread or other consumables we buy on a regular basis. Just look at that photo above ($5.39!). Can't you feel your jaw clenching at the mere sight of it?

High gas prices make us crazy, which is why the thought of raising them drives us even crazier. Never mind the rational explanations that inflation and fuel efficiency have eroded the value of the gas tax, or that it's no longer enough to fund our infrastructure, or that we've severed the gas tax from its traditional function as a road user fee. Those arguments are hard to make in Washington when the price at the pump is high and rising in Cleveland. And that's exactly what will be happening next May, if past trends in gas prices are any indication.

This suggests that December would be a great time to make long-term plans for funding our highways — not because of the political calculus in Washington, but because the dead of winter offers our best shot for thinking rationally about the topic.

What did the price of gas look like, you're wondering, the last time Congress raised the gas tax?

Toggle through the historic data yourself: