HONOLULU (KHON2) — What happens if lava threatens or closes the Saddle Road highway? KHON2 obtained a plan the State has made for how it would handle Highway 200 closure if it becomes necessary.

The updated plan, released on Wednesday, delineates closures near the 8 and 28 mileposts, enforced and manned, and signage on feeder roads in all directions. Again this is just a plan if closure becomes necessary. No closure is currently in place.

(Courtesy Hawaii DOT)

KHON2 spoke with Ken Hon, USGS, and Hawaii Island Mayor Mitch Roth about the plan, how likely it is to be triggered, and possible timing.

“As it as it moves down, when it hits about three to four miles away from the Saddle Road, everything completely flattens out in that area,” Hon explained.

He said it could be a matter of days depending on variables.

“Depending on speed, and also what the lava does, when it hits the flat, it could continue to move as a channelized ‘a‘ā flow, in which case, it wouldn’t spread very widely, and it would reach the the highway faster, or it might actually spread out as pahoehoe, in which case it could spread over a big area and that would slow it down significantly,” Hon said.

KHON2 asked Roth how the County is planning around possible closure of a major island thoroughfare.

“We’ve been meeting with all of our partners. One of those partners is the State Department of Transportation and they’ve come up with some plans. If Saddle Road gets cut off, or Daniel K. Inouye Highway (Hwy. 200) gets cut off, what will happen is people have to go around the coastal routes and people have been used to that.”

“But that will cause some traffic congestion. Our buses now go over that road and a lot of trucks go over,” Roth added. “Luckily right now, the bridges that we’ve been working on that and prevented trucks and buses from going over. Those bridges are within days of being completely repaired and so will be back to 80,000 tons of vehicles being able to go over, for example, the new bridge on the Hamakua coast, which has been out for several months.”

As of Wednesday morning, the flow is more than three miles from the highway. This plan is in place if closure becomes necessary due to the flow of Mauna Loa’s eruption.