Divisions deepen on U.S. transportation bills

* March 31 deadline for transportation legislation

* Boehner slows consideration of House bill

* Interest groups to step up lobbying

By John Crawley

WASHINGTON, Feb 17 (Reuters) - U.S. lawmakers dug in on Friday for a rough fight over transportation legislation that was forced off the road by partisanship and skepticism about where government is going to find the money to pay for infrastructure improvements.

New uncertainty settled over the House and Senate about whether members could bridge divisions over issues unrelated to road, bridge and transit construction and put the multibillion-dollar legislation back on track.

Congress faces a March 31 deadline to complete the matter before the latest temporary federal law funding transportation construction projects expires. Proponents are concerned that election-year politics will by early spring push transportation off the agenda.

"This legislation is too important for more delays," Senate Majority leader Harry Reid said before lawmakers broke for a weeklong recess. "We have to have bipartisan legislation."

Congressional leaders made transportation a priority for the early part of this year as a way to create jobs in a tough economy.

Expectations were high that both houses could pass their respective bills quickly and move to the more difficult task of negotiating a final, compromise plan.

But Republican efforts to use the legislation to advance unrelated objectives surfaced this week and slowed the progress of the Senate's two-year, $109 billion proposal. On Friday, Democrats failed to combine road and bridge planning, financing and transit aspects of the bill into a single package.

The technical setback for majority Democrats, which was expected, draws out the process further than anticipated and sets the stage for more work to appease conservatives.

It also gives Republicans more leverage and time to push amendments Democrats call obstructionist, including one to fast-track the Canada-to-Texas Keystone XL pipeline, which President Barack Obama put on hold.

Another would reverse a White House rule guaranteeing free birth control for women who work for religiously affiliated employers.

VETO THREAT

House Republican leaders continued on Friday to pare amendments that totaled more than 300 when voting on transportation-related measures kicked off on Thursday.

The avalanche was partly responsible for Speaker John Boehner's decision to slow consideration of the five-year, $260 billion House bill, with Republican support for the plan surprisingly in doubt over funding questions and other issues.

"We'll give our members the chance to participate in the debate and we'll finish this bill after the recess," Boehner said.

The White House weighed with Obama threatening a veto of the House bill.

The Obama administration objects to a number of House provisions, including the Keystone plan and a proposal to open the Arctic National Wildlife Refuge in Alaska to oil drilling. Republicans say new drilling could raise money needed to bridge big gaps in transportation funding.

Both passed the Republican-led House on Thursday but face stiff leadership opposition in the Senate.

Federal spending on transportation goes mainly to state and local governments as reimbursement for projects they plan and carry out. States are eager for a transportation funding blueprint as temporary spending measures make long-term project planning difficult.

Interest groups plan to lobby lawmakers over the Presidents Day recess. The AAA auto club, which advocates for members on highway infrastructure, said the March deadline was a cause for nervousness.

"The message AAA clubs will be sending is pretty simple and straightforward - act immediately to pass bill in both the House and Senate when you get back to Washington," said spokesman Peter Nonis.