Outgoing Senate Budget Chairman Kent Conrad (D-N.D.) surprised fellow legislators by announcing that he would offer as a budget proposal Alan Simpson and Erskine Bowles' debt reduction plan, which includes a gas tax increase.

It is unclear when or if Conrad will ask for a vote on the Simpson-Bowles language, which has been widely praised but not put into legislative text.

Among the myriad of debt-cutting reforms -- including a hike in the Social Security retirement age and cuts to defense spending -- the plan from former Clinton White House chief of staff Bowles and Republican Sen. Simpson of Wyoming would set up a gradual 15-cent increase in the gas tax starting in 2013. All of the money would go to the transportation trust fund, eliminating the need for future bailouts.

Spending in the fund would also be limited to revenues from the gas tax.

"What I am proposing is not partisan," Conrad said in a statement. "I am trying to break from the 'business as usual' practice that has gone on for too long."

Conrad, who said the deal offers a long-term vision because budget levels have already been set for the next two years, added that the plan "provides a comprehensive and balanced deficit reduction framework that we can build upon."

Although raising the gas tax -- last set to 18.3 cents per gallon in 1993 and not indexed to inflation -- has been politically toxic, it has gotten some recent play. Sen. Mike Enzi (R-Wyo.) introduced, then withdrew, an amendment indexing the tax to inflation at a recent Budget Committee hearing, which drew praise from both parties. And others have discussed possibly raising the tax to fix the transportation funding woes, although no proposal has gained serious traction.

Sen. Tom Carper (D-Del.), who had previously supported a gas tax increase proposal, commended Conrad's move, saying in a statement that he supported the plan's "balanced approach" that included "the shared sacrifice necessary to rein in our deficit."

Appropriations bill moves forward

Meanwhile, the Senate's Transportation Appropriations Subcommittee passed a Transportation, House and Urban Development bill that would set budget authority for transportation and housing at $53.4 billion for fiscal 2013, $3.9 billion less than 2012 levels. Total funding for the transportation and housing programs would be $105.5 billion, representing a more than 3 percent cut from 2012.

The subcommittee approved the bill on a 15-1 vote, with Sen. Ron Johnson (R-Wis.) as the sole "no" vote. Panel Democrats said the transportation funding measure would be one of very few infrastructure investment packages that might clear both chambers. Sen. Barbara Mikulski (D-Md.) praised its funding for the Washington metro system and for community block grants.

"It builds American, keeps America going, and creates jobs and infrastructure," Mikulski said.

The subcommittee approval sets up a vote in the full Appropriations Committee, along with the bill for Commerce, Justice, Science and Related Agencies, at 10:30 a.m. tomorrow.

Sen. Frank Lautenberg (D-N.J.) commended subcommittee Chairwoman Pat Murray (D-Wash.) and top Republican Susan Collins of Maine for their "bipartisan spirit" in drafting the bill, though he said it should have provided more for programs.

The bill would offer $500 million for the popular Transportation Investment Generating Economic Recovery, or TIGER, livability grant program, while also investing more than $2 billion in transit programs through the "New Starts" program. The latter represents an $89 million increase over fiscal 2012.

Highway funding would stay the same with $39.1 billion, while rail would see a $126 million boost for a total appropriation of $1.75 billion ($1.45 billion for Amtrak). However, there was no money set aside for high-speed rail development.

Johnson asked for a recorded vote on the bill, which he said fell into an overall spending pattern that would exacerbate the federal deficit.

Reporter Jean Chemnick contributed.