U.S. Rep. Tulsi Gabbard and U.S. Sen. Brian Schatz are working "every day" to persuade federal officials to rebuild lava-covered portions of Chain of Craters Road as a two-lane emergency evacuation route out of Hawaii island’s lower Puna District instead of only one lane, Gabbard said Wednesday.

Hawaii County officials are fronting the estimated $14.5 million cost to rebuild about 9 miles of Chain of Craters Road from Kalapana through federal land in Hawaii Volcanoes National Park that’s been buried by previous lava flows. While Hawaii County Mayor Billy Kenoi insists that residents of lower Puna need a two-lane emergency highway, the park superintendent reiterated the federal government’s position that Chain of Craters Road needs to be rebuilt on federal land as one lane of unpaved highway to reduce damage to ancient archaeological sites and endangered species.

Under the plan, traffic would move one way out of Puna through Kalapana and Hawaii Volcanoes National Park in the mornings and one way back toward lower Puna in the afternoon.

"We have emergency approval for this activity for one lane unpaved and we have our own national policy act regulations that we have to follow and that’s what our parameters are," said park Superintendent Cindy Orlando. "The National Parks’ position is that one lane meets the emergency needs."

On Wednesday, Gov. Neil Abercrombie issued an executive order that states that the state-owned portion of the 19-mile-long Chain of Craters Road is "hereby turned over to the County of Hawaii, in fee simple, for use as a county highway, and the County of Hawaii shall hereafter be responsible for its repair and maintenance as a county highway."

In a conference call with reporters Wednesday, Kenoi said lava spewing out of Kilauea Volcano could overrun lower Puna’s main artery — Highway 130 — in 15 days.

But the flow has slowed since the original predictions were made, said Steve Brantley, acting scientist-in-charge for the U.S. Geological Survey’s Hawaiian Volcano Observatory.

"It’s still moving, but it’s moving relatively slowly," Brantley told reporters. "At this point we’re not confident in being able to make a prediction that far off in time or in distance, either."

Gabbard, whose congressional district includes the neighbor islands, told the Honolulu Star-Advertiser that she, Schatz and Kenoi are working daily to get the federal government’s 5.4-mile section of Chain of Craters Road rebuilt as two lanes.

"I am working with Mayor Kenoi, as well as Sen. Schatz, to open up access for the 8,200 plus residents of lower Puna, especially after seeing what the residents of Puna have gone through with the hurricanes and tropical storms we recently had and this new situation with the lava flowing," Gabbard said.

Schatz, who sits on the Senate National Parks Subcommittee, was unavailable for comment.

Gabbard said she has yet to see evidence from federal officials that two lanes of Chain of Craters Road will cause more potential damage than one lane.

"I haven’t seen something that they’ve presented in terms of a documented study to back up that claim," Gabbard said. "I do understand that’s their position."

Orlando said Schatz’s office has received "information on resource impacts."

Chain of Craters Road would be open to only an estimated 4,000 vehicles per day if lava overruns Highway 130 — along with two newly restored evacuation roads, Railroad Avenue and a one-lane coastal road known variously as Beach Road and Old Government Road.

Traffic on the restored sections of Chain of Craters Road would be limited to 35 mph on the county-controlled portions and could be slower in the national park if the road is restricted to one lane, said Warren Lee, Hawaii County’s public works director.

Traffic on two-lane Railroad Avenue would be just 20 mph, Lee said. Traffic would move even slower on Old Government Road, Lee said.

"If you can go 20 mph, you’re risking your life," Lee told reporters. "But it will be posted at 20 mph. Believe me, some people go down there at 40 mph."

County officials originally estimated the cost to rebuild the two abandoned dirt roads at $800,000 to $1.2 million.

The projected costs have since grown to $3 million, Lee said.

"It certainly increased because some of the rock we had there, blue rock, that was difficult and had to be smoothed out," he said.

Tropical Storm Iselle, which blew across Puna on Aug. 8, showed the need for heavy emergency vehicles to quickly move in and clear roads and restore downed power lines, Gabbard said.

Fire trucks and other large emergency vehicles also will likely need to travel back and forth on Chain of Craters Road to get to stranded residents who need assistance, Gabbard said.

"We always have to be as sensitive as we can to our sacred sites and endangered species," Gabbard said. "But we have got to recognize the starkness and immediate need that this entire community of over 8,200 residents will face if there is no access whatsoever."