WASHINGTON (AP) — A controversial proposal to allow heavier trucks on interstate highways in an effort to save shippers time and money was rejected by the House on Tuesday, one of dozens of amendments expected to be offered to a sweeping transportation bill this week.

The amendment, defeated by a vote of 236-187, would have allowed states to increase the maximum weight for trucks to 91,000 pounds from the current 80,000 pounds. It was supported by manufacturers, shippers and trucking companies who said it would make freight shipments more efficient and reduce the number of trucks on the road. Rep. Reid Ribble, R-Wis., lead sponsor of the amendment, has said trucks leave dairy farms and paper mills in his district half full because they've reached the maximum weight limit.

The amendment was opposed by the railroad industry, which stood to lose business to trucks if it passed; safety advocates, who said it would lead to more traffic deaths; and most Democrats, who complained it would lead to more wear and tear on roads and undermine safety.

"We are facing a capacity crunch in the United States today," Ribble said, adding that freight tonnage overall is forecast to increase 25 percent in next decade. He noted that about half of states already allow heavier trucks on state and local roads. It would be safer, he said, to move those trucks onto interstates instead.

"That presumes moms, dads and kids don't use the interstate highway system. In my district, they do," shot back Rep. Michael Capuano, D-Mass.

The amendment was offered to a bill to set transportation policy for the next six years. It is the first major bill on the House floor since Rep. Paul Ryan, R-Wis., became speaker last week, and lawmakers plan to spend days debating scores of amendments. That reflected Ryan's promise to give rank-and-file lawmakers greater clout in shaping legislation — something they complained they lacked under Speaker John Boehner, R-Ohio, who resigned under fire last week.

The amendment has been the focus of an intense lobbying battle between the Coalition for Transportation Productivity, which represents industries supporting heavier trucks, and the Association of American Railroads, which represents freight railroads.

"The added truck weight will further destroy precious national infrastructure and cost taxpayers dearly," Edward R. Hamberger, president of the railroad associations, said.