The Mauna Loa lava flow continued to inch toward Daniel K. Ino­uye Highway on Friday, fed by the only robust fissure on the world’s largest active volcano.

The flow was advancing at an average rate of 150 feet per hour and was less than 2.7 miles away from the highway, also known as Saddle Road.

Scientists with the Hawaiian Volcano Observatory weren’t offering any predictions Friday as to when, or whether, the flow will reach the key central transportation link between the west and east sides of the island.

In their Friday night update, they said only that the flow’s travel rate would be highly variable “over the coming days and weeks” as it traverses the relatively level terrain.

“On flat ground, lava flows spread out and inflate. Individual lobes may advance quickly, and then stall. Additional breakouts may occur if lava channels get clogged upslope,” the update noted.

Earlier on Friday, Julia Hammer, University of Hawaii at Manoa volcanology professor, said the flow might reach the highway in five to seven days, based on its previous movement.

“But it might not even get to the road, depending on what happens upstream,” she said on the Honolulu Advertiser’s “Spotlight Hawaii” livestream program.

While Fissure 4 continues to be active higher on the mountain, it was described as sluggish with little to no eruptive activity. Even Fissure 3’s fountains were smaller.

But David Phillips, Hawaiian Volcano Observatory deputy scientist- in-charge, said Fissure 3 output has become more stable, and there is no indication that any less magma is being added to its lava flow.

Meanwhile, Hawaii island Mayor Mitch Roth declared the newly created viewing area on old Saddle Road a success after an estimated 2,000 people used it to park their cars for viewing the spectacle Thursday night.

“I went through there last night. It’s actually the best viewing available, a safe place to go,” Roth said.

Not only that, he said, but traffic on the highway seemed to be flowing a lot better as well — a welcome change from the bumper- to-bumper congestion and unsafe conditions that produced at least two accidents on previous nights.

Elsewhere, the Hawaii Emergency Management Agency sent a four-person team to Hilo to assist with the county’s emergency response effort.

The agency also said it has begun analyzing potential impacts to the Big Island economy, infrastructure and transportation network if the eruption were to damage Daniel K. Inouye Highway or other significant community assets.

“While the lava is moving very slowly at the moment and doesn’t pose an imminent hazard to populated areas, it’s still a hazard with huge destructive potential,” HI-EMA Administrator Luke Meyers said in a statement. “We wouldn’t be doing our jobs if we didn’t work to define the possible impacts and recommend ways to reduce or eliminate them.”

Meyers traveled to Hilo on Thursday with the HI-EMA team to meet with county officials and join a 2-1/2-hour overflight of the eruption area with the Civil Air Patrol.

The four-person team is expected to help civil defense officials with operations, planning and logistical challenges and work to match any needs with available resources and data.