A growing lava stream threatening homes and inching closer to a rural road on Hawaii's Big Island oozed forward in fits and starts this week, frustrating some residents but giving officials a window of time to prepare.

The narrow, leading edge of the lava flow is just 250 yards from the one-lane country road, which has been closed. Crews are working on an alternate route for remote communities in the Puna district in case the lava crosses a major thoroughfare.

The lava has sped up recently, advancing nearly 460 yards from Thursday morning to Friday, but it has since slowed again, officials said.

The flow's fitful nature is taking a toll on some Big Island residents, who got a brief reprieve from the advancing molten stream only to have to raise their guard again.

"This stop-and-go — it's going to be very frustrating for our residents," said Darryl Oliveira, director of Hawaii County Civil Defense. "It raises the anxiety level. It raises the concern."

On the other hand, the sporadic suspensions in activity gave emergency crews time to work on building another road and deal with a recent tropical storm that swept by the island, Oliveira said.

Crews near the leading edge have been wrapping power poles with concrete rings as a layer of protection from the lava's heat.

The recent acceleration came when the lava reached a gully, allowing it to move more efficiently like rain in a gutter, Oliveira said.

No evacuations have been ordered, and the residents of a home that is nearest to the flow already have left voluntarily.

Gov. Neil Abercrombie signed a request Friday for a Presidential Disaster Declaration asking for federal assistance to help local emergency crews.

Hawaii County Civil Defense crews are planning to go door-to-door Saturday to about a dozen homes to find out how many people might need shelter if the eruption continues, and to find any obstacles like abandoned cars or hazards that could be in the lava's path.

Oliveira said he would give residents three to five days' notice before an evacuation order, and he stressed that the community is not yet at that point.

Some long-term locals are used to the uncertainties of living near one of the world's most active volcanos.

"Because of what they've experienced over the course of their lifetimes, they were very accepting ... that this is nature's thing," Oliveira said. "But on the other hand, we have people who are new to the island who don't really understand how it's playing out and what to expect and having a harder time preparing."

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