Sen. Tom Coburn of Oklahoma had been insisting Democrats change the bill to eliminate a requirement that states use a portion of their federal highway funds for bike paths, walking trails and other transportation "enhancements."
John Hart, a spokesman for Coburn, said the senator agreed to give up his effort in exchange for assurances from Sen. Barbara Boxer, chairwoman of the Senate Environment and Public Works Committee, and Sen. James Inhofe, the ranking Republican member of the panel, that the enhancements funding requirement will be removed at a later point.
"States will have the ability to opt out and spend enhancement money on bridge repair and other priorities," Hart said in an email.
But Boxer said earlier in the day that she wanted to "reform" the enhancements program, not eliminate it. She declined to elaborate on what those reforms might be.
Once Coburn dropped his objection, the bill sailed through on a 92-6 vote. Democrats also easily turned back an effort by Sen. Rand Paul, R-Ky., to cut overall transportation funding.
The House passed the bill on Tuesday. The bill now goes to President Barack Obama for his signature.
The Senate vote marked "a good day for the American people," Senate Majority Leader Harry Reid, D-Nev., said afterward. "About 2 million people are breathing a sigh of relief because they're going to have jobs on Monday."
The bill extends the FAA's operating authority, which was due to expire at midnight Friday, through January. Authority for highway, transit and rail programs, as well as the federal gasoline and diesel taxes that provide the largest share of funding for the programs, which were due to expire on Oct. 1, are extended through March.
Earlier this week, Coburn had pointed to the nation's 146,000 bridges that are structurally deficient, saying it's wrong to require states to spend money on projects that don't enhance safety.
The enhancement programs amount to about 2 percent of the federal transportation budget, according to the Transportation Department.
A partisan standoff between House Republicans and Senate Democrats forced the FAA to partially shut down for two weeks this summer. Nearly 4,000 FAA workers were furloughed and more than 200 airport construction and safety projects halted, affecting tens of thousands of other workers. The government lost nearly $400 million in airline ticket taxes because airlines no longer had authority to collect the fees.
Long-term funding for the FAA expired in 2007 and highway programs in 2009. Both programs have been continued through a series of short-term extensions. The latest bill would be FAA's 21st extension and the highway program's eighth.
Transportation and aviation interest groups urged lawmakers to quickly turn their attention to reaching a compromise on long-term funding measures.
"The longer it takes to pass a multiyear (transportation) bill, the more expensive the problems are to solve," said Janet Kavinoky, vice president of the Americans for Transportation Mobility Coalition. "Conditions get worse; land, labor and materials get more expensive. Highway and transit investments facilitate national, regional, and local economic growth in the long term, and create direct jobs in the short term."