By Richard Stradling for The News & Observer
Rebuilding Interstate 40 through North Carolina’s section of the Pigeon River Gorge is going to cost a lot more than previously thought.
The N.C. Department of Transportation now expects that restoring about five miles of the eastbound lanes of the highway near the Tennessee state line will cost about $2 billion. That’s about $900 million more than NCDOT estimated last June.
That increase, along with fluctuating costs for other recovery projects, puts the current estimate for rebuilding roads and bridges in Western North Carolina at nearly $5.8 billion, up from about $5 billion a few months ago. By either number, Helene is by far the costliest storm NCDOT has ever faced.
Several factors contributed to the growing cost of the Pigeon River Gorge project. Most come down to having engineers being able to study the terrain and develop a plan for building back the highway foundation that the flooded river washed away, said Chris Peoples, NCDOT’s chief operating officer.
“We had limited information to put an estimate together,” Peoples told the state Board of Transportation last week. “We’ve got a contractor on board now. We’re working with them on progressing designs. We’ve got more geotechnical information.”
Swollen with water from Helene in September 2024, the Pigeon River washed away the bank along the highway and undermined the pavement, causing the eastbound lanes to collapse in 10 places in North Carolina and several others in Tennessee. Highway departments in both states reopened I-40 through the gorge last winter by converting the surviving westbound lanes to two-way traffic at a reduced speed.
Rebuilding the eastbound lanes will mean re-establishing the roadbed and building retaining walls as tall as 70 feet. Federal officials gave NCDOT permission to mine up to 3 million cubic yards of stone from just across the river in Pisgah National Forest and truck it across temporary bridges to restore what the river washed away.
The largest share of the increased cost — $430 million — is a result of the geotechnical studies that showed that bedrock along the highway was more variable and deeper than expected, requiring larger foundations for the retaining walls.
The goal, Peoples said, is to try to ensure the new eastbound lanes aren’t threatened by the river in the future.
“As you start investigating where bedrock is and those kinds of things, you start coming up with different solutions that you didn’t contemplate a year ago,” he said.
Some road rebuilding costs have gone down
NCDOT and its contractors have changed the expected costs of all the big Helene repair projects in recent months, as they get better information.
In several cases, the numbers have gotten smaller. For example, NCDOT now expects to spend $266 million rebuilding 18 miles of roadway and seven bridges along the Toe and Nolichucky rivers north of Burnsville; that’s $114 million less than earlier estimates.
The upshot is that while the I-40 repairs increased $900 million, NCDOT’s overall estimated cost of Helene reconstruction rose $804 million. Those numbers will likely change again, said Mark Newsome, the department’s chief financial officer.
“I feel more confident every month that we go,” Newsome told the board. “But I think we may have some additional changes.”
The state expects the federal government, through the Federal Highway Administration and the Federal Emergency Management Agency, to pay nearly $4.8 billion for Helene road and bridge rebuilding. That would put the state’s share at $978 million, which is more than NCDOT spent on repairs from all previous storms combined since 2016, including two hurricanes, Matthew and Florence, that devastated the eastern part of the state.
The rebuilding of I-40 is still in its early stages; the eastbound lanes are not expected to reopen to traffic until late 2028. Though unlikely, it’s possible the final cost could come in somewhere under $2 billion, Peoples said.
“We can’t say that that’s not a possibility,” he said. “But I-40 is a complex project.”