Bush has signaled he will sign the bill despite earlier calling it a gimmick and threatening a veto. Officials said the money was designed to ensure timely reimbursement to the states for projects contained in a $286 billion highway bill that passed in 2005 — a measure that included about 6,300 earmarks that lawmakers inserted at an estimated cost of $24 billion.

The $8 billion would come from the Treasury and is designed to make up for insufficient federal gasoline tax revenue, which pays for highways, bridge repairs and similar construction projects.

Asked on Thursday for McCain's views, Rogers initially was noncommittal. He said in an e-mail that Transportation Secretary Mary Peters' request "for an immediate federal bailout of $8 billion is just another example of how Washington is broken. ... The federal transportation must be redirected towards the nation's true needs and away from pork-barrel projects."

Subsequently, he said McCain "did not object to the bill because we need to keep improving our nation's infrastructure. ... President McCain will fight for a pork-free highway bill where money is spent on real priorities and not on wasteful or non-urgent projects."

McCain's White House rival, Sen. Barack Obama of Illinois, issued a statement supporting the measure when it passed the Senate.

According to Democratic estimates, which cite data from the Federal Highway Administration, the shortage threatens prompt reimbursements for projects that involve nearly 380,000 jobs in a time of rising unemployment. The money would be spread across all 50 states.

McCain has made opposition to earmarks one of the centerpieces of his campaign for the White House. "I got an old ink pen, my friends, and the first pork barrel-laden earmark, big-spending bill that comes across my desk, I will veto it," he said this week at a rally in suburban Virginia.

"You will know their names. I will make them famous and we'll stop this corruption."

Yet governors as well as many lawmakers customarily take the view that highway construction is a political winner with constituents. And while McCain does not seek earmarks, Palin did while mayor of Wasilla, Alaska, and again as governor, and Obama has also.

The National Governors Association appealed to congressional leaders this week to approve the funding. A letter by Michigan Gov. Jennifer Granholm, a Democrat, and South Dakota Gov. Mike Rounds, a Republican, said the money "will enable states to continue to finance highway projects that improve safety, ensure rural and urban mobility and access, increase the mobility of people and goods, and promote a sound economy through well-paying construction jobs.

The legislation's popularity was unmistakable as it made its way through Congress. It cleared the Senate on a voice vote and then passed the House by a margin of 376-29.

(This version CORRECTS money reimburses states for their prior expenditures.)