Lava from the weakening Mauna Loa eruption is no longer threatening Daniel K. Inouye Highway, but businesses that rely on the cross-island road to transport merchandise, supplies and workers are standing by in case that changes.

The latest update from the Hawaiian Volcano Observatory says lava has ceased feeding the main 12-mile-long flow, which has stalled 1.9 miles from the highway.

“That’s really good news,” said state Department of Transportation Highways Administrator George Abcede.

He said last week that his agency was investigating the possible use of a Hawaiian Electric maintenance access road to bypass any lava flows that might block the vital highway, more commonly known as Saddle Road.

“Right now we’re looking at the viability of the access road farther north and getting ready to put things in place in case we actually have to go build that road, so that when the time comes we can just go ahead and start,” Abcede said.

“Everything depends on how fast it’s moving, because if it’s moving slow like this and it did finally overrun the highway, an access road temporarily for a little while would work, but there’s no other way.”

Lacking a bypass route, closure of the highway would force commercial and commuter traffic onto Hawaii Belt Road as the main alternative route between Hilo and Kona. That would extend travel times while increasing costs and possibly disrupting supply chains.

“It’s a hot topic,” said Miles Yoshioka, executive officer of the Hawaii Island Chamber of Commerce, before scientists confirmed the eruption was diminishing. “Different businesses are taking it to different levels. For our retailers and whole-salers and building material suppliers, they’re preparing to build up the stock levels of their most needed goods and stock up their warehouses.”

When the eruption kicked off Nov. 27, HPM Building Supply immediately assembled an internal planning team in anticipation of possible disruptions should the highway be overrun by lava, according to Darryl Oliveira, HPM director of risk management. The longtime local business proactively began increasing inventory at its retail stores and lumberyards in Hilo, Kona and Waimea to maintain “seamless and uninterrupted” customer service, he said.

Oliveira, who headed the county’s Civil Defense Agency from 2013 to 2016, said the company even went so far as to redirect inbound shipments of materials and supplies for its West Hawaii branches from the Hilo port to Kawaihae Harbor on the west side of the island.

Oliveira and other business leaders also have been conferring with county, state and civil defense officials to ensure Hawaii Belt Road, which runs north from Hilo along the Hamakua Coast before turning west through Honokaa and Waimea and dropping into Waikoloa and Kailua-Kona, will be ready to handle any heavy increase in traffic.

DOT REPORTED that all bridges on the route “have been returned to the unposted weight limit of 40 tons” and that there will be no permanent lane closures should Hawaii Belt Road be called into duty as the primary route between East and West Hawaii.

On Dec. 1, DOT reopened the northbound lane on Nanue Bridge at mile marker 18.5; it had been closed for emergency repairs after one of the bridge’s support columns was damaged in a fatal vehicle crash in February.

Even fully restored, Hawaii Belt Road means longer travel times for freight hauling and deliveries as well as workers getting to their jobs. Yoshioka said some businesses are concerned about retaining workers who would face commuting difficulties during a prolonged highway closure.

Oliveira said HPM Building Supply was ready to help those workers by offering interim positions at branches closer to their homes.

Craig Anderson, vice president of operations for Mauna Kea Resort, said about 8% of the resort’s 1,200 employees commute from East Hawaii. The resort was considering stipends or modified work schedules for those affected by a highway closure.

So far the county’s Hele-On bus express route between Hilo and Kailua­-Kona via Daniel K. Inouye Highway has not been affected by the eruption, according to Mass Transit Administrator and General Manager John Andoh. There are four round trips daily carrying both commuters and tourists. A one-way trip from start to final stop generally takes two hours and 45 minutes, he said, but if rerouted along Hawaii Belt Road, the journey will take about a half-hour longer.

SADDLE ROAD was originally built by the Army as a one-lane road in 1942 to provide access to military training facilities. The road was widened and paved over the years but remained a sketchy proposition for motorists, and rental car companies at one time banned customers from driving the route.

In the 1990s, Daniel Ino­u­ye used his influence as a U.S. senator to lead the effort to build and improve nearly 48 miles of roadway to provide safer travel and economic opportunities for Hawaii island residents. The project, conducted in phases, spanned several decades and cost approximately $316.5 million in state and federal funding. The final 6-mile phase opened in October 2017.

The highway extends from the outskirts of Hilo westward to Mamalahoa Highway, passing through the saddle between Mauna Loa and Mauna Kea and climbing nearly 5,500 feet from its eastern terminus to midpoint.

Restoring any road once it’s been covered by lava is no easy task, and there are few shortcuts. Abcede recalled a previous occasion years ago when a Kilauea flow inundated a state roadway.

“It’s basically waiting for the lava to cool enough so we could actually build something on top of it,” he said. “The last time it happened, we had to wait a couple of months for the lava to cool and there was enough of a crust to build on top of it. … And it depends on how thick the lava is. Sometimes it can be 20 feet thick. We can’t just take it all out if it’s still hot.

“Even when we did it the last time, it still wasn’t easy. You just can’t pave a regular road.”

Hawaii County is still working to restore roads inundated by the massive 2018 Kilauea eruption in Lower Puna. The county and Federal Emergency Management Agency agreed on an $82 million damage assessment to be used for road repairs, and the county timeline to complete the work extends into 2025.

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STAY INFORMED

For updates on the Mauna Loa eruption, visit hawaiicounty.gov/civil-defense.