A state lawmaker said that he will try to block federal legislation that would pave the way for heavier trucks on the nation's highways.

Rep. James E. Casorio Jr., D-Irwin, said on Tuesday he will propose a resolution urging Congress to pass a pending bill that would prohibit states that have not already done so, including Pennsylvania, from allowing trucks over 80,000 pounds to travel on the national highway system.

A separate measure sponsored by Rep. Michael Michaud of Maine would allow states to increase the weight limit to 97,000 pounds.

"The large trucks traveling Pennsylvania's highways now already present a significant safety hazard," Mr. Casorio said. "They also cost the state and local governments millions of dollars a year in damage to highways and bridges."

The trucking industry contends that allowing heavier trucks would increase productivity by making it possible to transport more goods with fewer trucks, and that the larger trucks would be no less safe than current trucks.

Mr. Casorio said such claims have been refuted by safety groups.