Congress will consider every option available to deal with the funding crisis facing transportation infrastructure, two of the federal lawmakers who play the biggest role in setting transportation policy said Thursday.

Rep. Bill Shuster, the Republican chair of the House Transportation and Infrastructure Committee, and Sen. Barbara Boxer, the Democrat who leads the Senate Environment and Public Works Committee, spoke before a conference of state highway officials Thursday afternoon.

"I'm going to be very, very upfront with you: This is a huge challenge we face, and it's a challenge that we have to solve," Boxer said.

The two lawmakers said they've already started discussing with each other the successor to MAP-21, the highway bill Congress passed last year that is set to expire in 2014. Historically, Congress has passed longer-term highway bills; the short duration of MAP-21 means that lawmakers are already debating the next highway bill at the same time they're overseeing the implementation of the current one.

The shorter-term bill was passed last year largely because Congress struggled to agree on a way to pay for the legislation. Ultimately, lawmakers cobbled together money through mechanisms largely viewed as accounting gimmicks. The move means that as Congress crafts the next highway bill, it will almost certainly have to more substantively address the issue of funding -- or otherwise make big cuts.

That challenge comes as a time when many policy experts are calling for an increase in the gas tax to solve the problem, but many lawmakers still find a gas tax hike politically unpalatable. Shuster, who has taken over a position previously held by Rep. John Mica, will play a crucial role in shepherding a highway bill through Congress next year.

"I believe we have to look at every option out there," Shuster said. "I don't rule anything out. I don't rule anything in."

Boxer echoed that view. "We have got to find a source of funding for that [Highway Trust Fund] that makes sense," Boxer said. "It's wonderful to know everybody says everything should be on the table. This is not going to be easy." She implored the transportation community to share their ideas with their Congressional representatives, and in particular, continue to the make the case for transportation investment.

Shuster said since he's taken over the committee, he's tried to emphasize to his colleagues -- especially the conservative ones -- that "there is a federal role in transportation." Some conservatives have encouraged the idea of devolving federal responsibility for the country's transportation infrastructure to states. But Shuster said that from the nation's earliest days, the federal government has played a crucial role in orchestrating transportation policy.

Shuster also said he's been trying to rebuild bipartisan relations within the committee and is frequently communicating with Rep. Nick Rahall, the committee's ranking member. Under Mica's tenure, the committee had deep partisan divides; Boxer's public works committee in the Senate, on the other hand, has been heralded as a model of bipartisanship.

Both Shuster and Boxer say they favor the user-pays principle -- the idea that those who use the road system should pay for it -- which is the basis of the gas tax. At the same time, that gas tax is proving financially unsustainable, since it hasn't increased in nearly 20 years, and improvements in fuel efficiency mean people are paying less money to drive.

Politically, a move toward a national vehicle-miles traveled fee may not be practical yet, Shuster said, adding that the issue merits close attention nonetheless. Lawmakers opted against exploring VMT in the latest highway bill.

Shuster also touted a plan that proved to be controversial and created partisan divides last year:  using royalties from gas and oil found on federal lands to hep fund transportation.

The chairman also said he'll be spending much of his time trying to educate his colleagues in the House about the Water Resources Development Act, which addresses the country's inland waterways, an important component of the freight shipping network.

Congress hasn't passed the legislation, known as WRDA, since 2007. It's so long ago that many if not most members of the House don't know what it is, Shuster said, adding that passage of a new WRDA bill will be one of the committee's first tasks.

Also on the docket: railroad reauthorization, which Shuster said the committee will address later in in the year. Shuster said he doesn't agree with Republicans who believe Amtrak should be done away with and left to operate entirely without government support, but he believes the size of Amtrak's subsidies can and should be shrunk. Shuster, reiterating the view of many conservatives, also argued that the federal government should take a more targeted approach to high-speed rail and focus on the Northeast Corridor, where the combination of a big population center and crowded airways make it a natural fit.