Lava from the Mauna Loa eruption closed the distance to Daniel K. Inouye Highway to just 1.5 miles, Hawaii County Civil Defense reported Tuesday afternoon.
But although the lava is still approaching the highway, Mike Zoeller, geologist for the U.S. Geological Survey’s Hawaii Volcanoes Observatory, said Tuesday that the lava has continued to slow down as it crosses the flat land on the saddle.
Over the 24 hours leading into Tuesday morning, the lava moved at a rate of approximately 68 feet per hour.
An HVO statement advised that as the lava slows further, its pace will become more erratic as the lava spreads out and inflates. This makes it difficult to estimate when or even if the flow will reach the highway.
With the highway still open in both directions, lava viewers have continued to flood the mountain. More than 14,000 vehicles have traversed the county’s lava viewing route since it opened last week.
The Traffic Hazard Mitigation Route — a 4.5-mile one-way stretch of Old Saddle Road from the Gilbert Kahele Recreation Area to Pu‘u Huluhulu — opened Thursday in order to reduce crowding on Daniel K. Inouye Highway.
Since then, Lt. Col. Kevin Cronin, garrison commander for the Pohakuloa Training Area, said thousands of vehicles have traversed the route.
Mayor Mitch Roth said Tuesday that more than 4,000 vehicles traveled the route on Saturday, more than 3,700 on Sunday and more than 2,500 on Monday.
Roth reminded drivers to clean up after themselves and to drive with caution both on the route and on the main highway.
He said that the biggest threat to people is not from the lava itself but from the traffic conditions.
The Hawaii Army National Guard sent 20 guardsmen to the island Tuesday to help manage the traffic. Ten guardsmen will be posted along the mitigation route for 12-hour shifts as long as the situation requires their presence, according to a Hawaii County press release.
“Guardsmen are here to help with the increased traffic along our Traffic Hazard Mitigation Route,” said Maurice Messina, Director of Parks and Recreation, in a statement. “They’re here to be aloha ambassadors, ensuring that motorists remain on the appropriate roadway and out of restricted areas, especially as visibility lessens with the weather.”
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.
