Congestion on the Beltway, seen here — and traffic across the country — is on the Senate’s agenda this week. (Win McNamee/Getty Images)

A bill providing funding for the nation’s highways, bridges and public transportation systems failed a test vote Tuesday, but Senate leaders signaled they still hoped to reach a deal to allow for a final vote.

Senators voted down a motion, 52 to 44, to proceed to a final vote on the two-year, $109 billion bill packed with funding for road projects and reforms designed to bolster the safety of the nation’s trains, trucks and buses. The bill’s backers — including Democrats, some Republicans, labor unions and the U.S. Chamber of Commerce — say it will help create or sustain more than 2 million jobs in the next two years.

Aides on both sides of the aisle said Tuesday morning that leaders were close to striking a deal to permit the consideration of amendments not directly related to the legislation, and other related amendments, before final passage by Thursday.

Ahead of the vote, Democrats blamed Republicans for tying up the measure even though the general thrust of the bill enjoys bipartisan support. Among other amendments, Republicans have sought votes to authorize the completion of the Keystone XL pipeline and last week failed to earn enough support to expand conscience exemptions to the Obama administration’s new birth control coverage rule.

“Republican leaders have wasted almost a month of the Senate’s time obstructing this valuable measure for political reasons,” Senate Majority Leader Harry M. Reid (D-Nev.) said Monday.

If the transportation bill clears the Senate by week’s end, attention will shift to the House, where Speaker John A. Boehner (R-Ohio) has abandoned plans for an ambitious five-year transportation bill in favor of a more modest 18-month measure that also faces opposition from conservative lawmakers.

Boehner told reporters Tuesday that he is still “trying to find common ground” with his colleagues on the highway bill and said consideration of the Senate’s bill “is an option.”

Once the Senate sorts out transportation funding, it is expected to vote next on whether to confirm 19 nominees to federal judgeships. Reid has said he may hold up or down votes on each nominee if Republicans block his plans to confirm the judges as a group.

Follow Ed O’Keefe on Twitter: @edatpost

More from PostPolitics:

The Fix’s guide to Super Tuesday

How is the Roberts Court unusual? A law professor counts the ways.