President Obama pressed Congress on Wednesday to pass the transportation piece of his stalled $447 billion jobs bill, saying it "makes absolutely no sense" to have more than a million construction workers sitting around when there are repairs to be made, including to the Potomac River bridge where he spoke.

The Senate is expected to vote Thursday on whether to take up the measure -- $50 billion for road and bridge repair and $10 billion to attract private money to help finance such construction. But like Obama's earlier jobs proposals, this piece is expected to be unanimously opposed by Republicans and a few Democrats who object to any new spending and a proposed new tax on the wealthy to help pay for it.

Obama said the nation's aging transportation network costs American businesses and families about $130 billion a year, calling it a drag on the overall economy. He said failure to act could cost the country hundreds of billions of dollars and hundreds of thousands of jobs by the end of the decade.

Obama said the public supports him and that Congress would have to answer to their constituents if they don't pass it.

"There's no good reason to oppose this bill. Not one," he said at the foot of the Key Bridge, which connects the District of Columbia and Arlington, Va. "And members of Congress who do, who vote no, are going to have to explain why to their constituencies. The American people are with me with this. And it's time for folks running around spending all their time talking about what's wrong with America to spend some time rolling up their sleeves to help us make it right."