Environmental "radicals" and "extremists" stand in the way of the nation's transportation infrastructure being updated, a congressman said Monday.

"What's holding it up is environmental regulations and red tape," U.S. Rep. John Duncan Jr. said.

Rep. Duncan was speaking during a workshop of the Tennessee Municipal League's 70th annual conference at the Chattanooga Convention Center on how to pay for the nation's deteriorating highways while looking at future demands. He serves as the ranking Republican on the Highways and Transit Subcommittee of the U.S. House Transportation and Infrastructure Committee.

Environmentalists immediately disagreed with Rep. Duncan's assertions.

Trip Pollard, director of transportation for the Southern Law Environmental Center, said the congressman's ideas were a "myth," and several studies had been conducted on why long delays occurred during road building.

"The major cause of delay is locality, picking a wrong location for the project, and funding," Mr. Pollard said. "Funding is the main issue."

He said Congress actually instituted regulations recently streamlining environmental reviews. Last year the Tennessee Department of Transportation also conducted a major overhaul of environmental reviews to make things go more quickly.

Sierra Club spokesman Josh Dorner said the nation needs a reallocation of transportation spending with less emphasis on roads.

"Highway projects are wasteful," he said. "Building more roads leads to more cars, which leads to more pollution."

But Rep. Duncan said that with gas taxes not producing as much revenue as they once did, he would support raising the taxes. However, he said he would support it only if it came with provisions of more domestic oil exploration and allowing more drilling.