Lava From the Mauna Loa Volcano Could Sever a Major Highway on Hawaii's Big Island

The US Geological Survey says the lava flow from the erupting volcano is less than 3 miles from the Daniel K. Inouye Highway that crosses the island of Hawaii.

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A line of vehicles heading towards a lava flow
A line of cars going to visit a virtually unstoppable force of nature
Photo: Ronit Fahl / AFP (Getty Images)

A lava flow is heading toward one of the most important highways in Hawaii, and there’s not much anyone can do to stop it. According to the United States Geological Survey (USGS), Mauna Loa, one of the five volcanoes that form Hawaii’s “Big Island,” began erupting at approximately 11:30 p.m. on November 27th. Mauna Loa, the world’s largest active volcano, started spouting fountains of lava close to 150 feet high. As the eruption continued, it became evident that the flow of lava was endangering the Daniel K. Inouye Highway. And it’s not like you can just redirect hot lava.

A status report published on Sunday by the USGS stated that the lava flow front was 2.25 miles from the Daniel K. Inouye Highway. This road is the only inland connection between the Big Island’s two most populated areas, Hilo on the east coast and Kailua-Kona on the west coast. The report also stated that the flow was advancing at an average speed of 40 feet per hour (0.0076 miles per hour), slowing from a peak of 0.025 miles per hour reported on Thursday. But the USGS pointed out that the flow’s speed and direction could be highly variable, making it difficult to predict when, or if, the hot laval will reach the roadway.


There isn’t much that could realistically be done to stop the lava flow. Any potential measure to divert the flow would be prohibitively expensive and unlikely to succeed. In 1935, the U.S. Army Air Corps bombed a Mauna Loa lava flow in an effort to redirect it, which did precisely nothing. In 2001, 30 bulldozers built earth and stone dikes to divert a Mount Etna lava flow in Sicily, Italy, which proved far more successful than bombing lava but was by no means a guaranteed success.

A map representation of the highway's potential closure between mile posts 8.8 and 28
HDOT’s plan for volcanic highway closure
Graphic: Hawaii Department of Transportation

The Hawaii Department of Transportation (HDOT) hasn’t yet closed the Inouye Highway, but has published preliminary plans to do so. The current HDOT plan would close the roadway between mileposts 8.8 and 28. People driving from one side of the island to the other would have to use the island’s coastal highways, Highways 11 and 19. If the plan is put into action, residents would only get 6 hours’ notice before the detours were put in place.