The Senate may have engaged in a shocking display of bipartisanship Tuesday by moving toward passage of a two-year transportation spending plan, but don’t expect the House to follow suit just yet.

Under normal circumstances, bipartisan approval of a highway bill would ratchet up the pressure on the House to quickly pass the measure.

But this year is anything but normal, and GOP aides said ongoing rifts within the Republican Conference continue to make the path forward unclear. Because GOP leaders want to tackle health care and budget legislation first, these aides said, a long-term transportation bill isn’t likely until sometime next month. That means Congress will probably have to pass a short-term extension first.

“Some sort of short-term seems likely. … Even if we were to just accept the Senate bill as is, there are some practical issues” to getting it done before the end of the month, a senior House GOP aide said Tuesday.

Senate Democrats are urging the House to take up the bipartisan Senate measure in order to avoid a short-term extension. The Senate was working its way through a series of noncontroversial amendments. Senate Democratic leaders had hoped to finish the measure this evening, but ended up punting final passage to Wednesday so Senators could attend the engagement party of Sen. Susan Collins (R-Maine).

Senate Republicans were less fervent about taking up the Senate measure, but said they do want the House to act.

“I hope they do something on the issue,” said Sen. John Thune (S.D.), chairman of the Republican Conference. “Whether the House decides to use the Senate vehicle or comes up with something of their own remains to be seen, but I hope that they will act on a highway bill over there.”

Thune said the highway measure is more complicated than the House-passed small-business jobs bill that Senate Republicans are calling on Senate Democrats to pass.

The transportation bill “has more moving parts to it … and more elements that create controversy than the JOBS bill,” he said. “The JOBS bill is such a no-brainer to me. … We could do this by the end of the week.

“The highway bill is arguably going to take a little bit longer; there will be some things that the House might object to that the Senate did,” Thune continued. “But I hope in the end that we can figure out how to get a bill through because, in the end, I don’t think it’s helpful to have these extensions that we have been doing and not have some sort of certainty in place for the people out there who rely on the federal highway program.”

While Speaker John Boehner (R-Ohio) is not expected to make a final decision on how to proceed with transportation legislation until Members return from recess next week, it appears likely Republicans will take up some version of the Senate’s measure, but only after a short-term bill is passed to give the House more time.

According to one source, the need for an extension is the byproduct of scheduling realities on the chamber floor. Some are mechanical — because the Senate’s bill includes revenue provisions, which are required to originate in the House under the Constitution, the House will have to “clone” the bill. With the GOP’s three-day rule still in effect, the process of even bringing the bill to the floor could take four days or more, burning an entire week.

Other problems, however, are more political in nature.

The transportation bill butts up against the Republicans’ desire to pass a budget before the end of the month or lose one of their politically potent attacks on Senate Democrats. And while internal divisions are also threatening their ability to pass a budget, most Republicans seem convinced some agreement between conservatives and appropriators will be worked out.

With the two-year anniversary of the passage of President Barack Obama’s health care reform legislation next week — and oral arguments over the law scheduled for the following week in the Supreme Court — House Republicans also want to take the opportunity to resurrect the ugly fight over health care.

As a result, Boehner and House Majority Leader Eric Cantor (R-Va.) are expected to bring legislation repealing the Independent Payment Advisory Board, a key part of the law that would set reductions to Medicare payments, to the floor. House Members are also expected to hold numerous events around the anniversary and oral arguments in the next two weeks.

Still, outside groups are hoping to pressure the House to act on the highway bill sooner. The Laborers’ International Union of North America is running a radio ad in Boehner’s district, including cities of Dayton, Columbus and Cincinnati.

The ad makes the analogy that Congress’ failure to act forces Americans to play Russian roulette when they cross structurally deficient or obsolete bridges. “A fourth of the nation’s bridges are deficient or obsolete, and the average bridge is now 45 years old, dangerously close the average bridge lifespan of 50 years,” the group said in a release Tuesday.