Environmental regulators meeting Thursday in Raleigh ruled out some of the state Department of Transportation's ideas for protecting N.C. 12 from storm damage, but they agreed to consider elevating parts of the Outer Banks road on long bridges.

Concerned about harm to the Pea Island National Wildlife Refuge south of the N.C. 12 bridge over Oregon Inlet, the state and federal agencies vetoed options to protect the highway with heavy beach renourishment and dune construction.

And they turned down a suggestion to move N.C. 12 slightly to the west, where it would run through sensitive marshes in the bird sanctuary, a DOT spokeswoman said after the two-hour meeting.

But at the suggestion of a U.S. Fish & Wildlife Service biologist, the group agreed to consider a new idea: a seven-mile-long bridge that would veer west from N.C. 12 just north of a new inlet created in August by Hurricane Irene, curving across Pamlico Sound and hooking back into the highway in the village of Rodanthe.

DOT engineers frequently seek guidance from a group of state and federal regulators as they plan road projects that ultimately will need their agencies' approval. The group will reconvene in January for more discussion of these options:

Keep N.C. 12 on its present path but lift the pavement 25 feet into the air on a two-mile bridge across the new inlet in the wildlife refuge - and on another long bridge a few miles farther south, ending in the village of Rodanthe.

Replace the Rodanthe roadway bridge with a longer structure that would curve out into Pamlico Sound to bypass the storm-vulnerable area at the north end of Rodanthe.

Replace both roadway bridges with a single seven-mile bridge that would run south through Pamlico Sound to Rodanthe.

Jim Trogdon, DOT's chief operating officer, said the two bridges on the current N.C. 12 route seem most likely to win approval. DOT hopes to award contracts next year for both projects.

If the work starts less than two years after the damage caused to N.C. 12 by Hurricane Irene in August, DOT would be able to pay for the road with federal emergency funds, rather than carve the money out of regular highway allocations.

"This is why we're moving ahead so rapidly," Trogdon said.

Julie Youngman, an attorney with the Southern Environmental Law Center, said environmental regulators had rejected DOT's options for N.C. 12 a few years ago, when they were broached in connection with a contract to replace the Oregon Inlet bridge, which was awarded in July.

The proposed bridges for vulnerable sections of the road will effectively move N.C. 12 into the ocean in coming decades, as the barrier island migrates in the other direction, she said.

"They'll just keep raising sections of N.C. 12 up onto bridges as the island erodes under them toward the west, and can no longer hold that section of the road," Youngman said. "The result is a long bridge out in the ocean, to the east of the island."

Stanley R. Riggs, a coastal geologist who published a book this year on North Carolina's barrier islands, said the bridges would stabilize parts of N.C. 12 for a few years, but at a high cost. Other sections of the island also are vulnerable to heavy storm damage, he said.

"The question comes up as to whether a road-and-bridge system can even begin to survive for the time they're talking about, without breaking the state," said Riggs, an East Carolina University professor. "The feds don't have enough money to keep that road in place.

"You spend all that money on two bridges - and then an inlet opens up just a few miles down, where you don't have bridges. The shoreline continues to move west. You do not want a bridge in the surf zone, and it will be in the surf zone."

Trogdon said that won't be a problem.

"If we can design a bridge that can withstand the energy of the Oregon Inlet, we can design a bridge that can withstand the wave energy of the swash zone on the beach," he said.

Siceloff: 919-829-4527 or blogs.newsobserver.com/crosstown or twitter.com/Road_Worrier/