The gimmick, called "pension smoothing", allows companies to set aside less for their retirement commitments now, which means higher profits and a higher tax bill. But that just means they have to pay more later, which means lower profits and a lower tax bill. In other words, the revenue source for highway projects across the nation has all the structural soundness of a sand castle.
If it sounds like the opposite of how a well-run enterprise should be run, that's because it is. Indeed, it's a classic example of the kind of counter-productive short-term thinking that Washington politicians have often criticized American business for.
Call it democracy or, if you are more jaded, politics. But it's the only way Washington rolls in 2014.
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Democrats point to crumbling roads and bridges and want higher spending levels. Republicans insist government spends too much and oppose anything revenue measure that can be called a tax increase.
A bipartisan Senate plan to raise the gas tax—which has remained unchanged for two decades as more fuel-efficient cars have eroded its value—has no chance in the House.
Neither party has the power to simply impose its will.
The results: Nearly all business on Capitol Hill has halted. Even legislation that both parties agree on—on energy efficiency earlier this year, and on hunting and fishing rights more recently—can't reach the finish line. Sometimes it's because one party wants to deny a sponsor of the other party an achievement that has value in this fall's campaign; sometimes it's because votes on unrelated amendments might prove politically embarrassing.
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The only good news is that Washington retains the capacity to act in moments of genuine crisis. Congress passed the Wall Street bailout in the home stretch of the 2008 presidential campaign when the alternative was financial collapse. It passed the fiscal cliff deal at the end of 2012 when the alternative was an economically damaging tax increase for every taxpayer.
Though Congress has initially balked, chances are good that lawmakers will approve supplemental spending to ease the crisis of unaccompanied children from Central America on the southern US border. The specter of unchecked border crossing and homeless children is too much for even gridlocked legislators to ignore.
Read More Pothole pain: The cost of this winter's pitted roadways
And the same is true of the highway bill. Infirm as it is, Congress retains some sense of when it's about drive into a wall. The potential halt of road repair and construction in every state is one of those walls.
The last minute turn away won't be pretty. But for beleaguered American voters, at least it's better than a crash.