Yesterday, the House passed yet another extension of the federal surface transportation bill. This one also goes for 90 days and would take the highway trust fund from June 30 to September 30, 2012.

As expected, House Republicans attached some riders to the bill, including one that drew a White House veto threat. The extension would force an immediate approval of the full Keystone XL pipeline, from Canada to Port Arthur, Texas. It also included an amendment that would ban the EPA from any regulations on coal ash, a toxic by-product of the coal-burning process.

But the surprising part of this was the margin of the vote in the final passage. 69 Democrats, including leadership figures James Clyburn and John Larson, voted for the bill, and the 293-127 is at the 2/3 level that would be required to override the aforementioned veto from the President. 14 Republicans voted against the extension, with most of them on the hard-right side of the caucus, wanting no federal role for transportation at all.

The rationale from Democrats is that this sets up a conference committee for the transportation bill, and that they supported it just to get to a conference. The expectation is that the EPA regulation ban and Keystone XL would get stripped out at that time.

But the conference would potentially not extend highway funding beyond that 90-day stopgap. The Senate version of the bill authorizes funding for two years. But I don’t see how that gets through the House. And there are significant differences between the two bills, particularly on energy, where the House wants to pay for additional funding for expanded domestic drilling.

Perhaps the two sides can hammer out a longer-term deal, though I doubt it (Transportation Secretary Ray LaHood said flatly “There will not be a bill before the election”). And there are a couple positive surprises in the House legislation. The House version drops the effort to sever the link on mass transit funding, removing the dedicated amount from the trust fund that goes to that purpose. So this ensures mass transit gets a share. In addition, the bill includes a provision that mandates that 80 percent of all the proceeds from Clean Water Act fines for the BP oil disaster go to five states for restoration of the Gulf Coast. We have seen how that region continues to be devastated by the disaster, so any funds that can work to offset that would be positive.

Still, it’s unlikely that we’ll get anything but short-term extensions through the election. And this comes from the Republicans who decried “uncertainty” as a headwind for the economy. With long-term projects like infrastructure, uncertainty on funding actually comes into play.