PORTLAND Freezing temperatures and snow followed by a warm up with rain is the perfect setup for landslides, and the Oregon Department of Transportation is watching problem spots in and around the Portland Metro area.
Crews were checking 120 known problem spots as they drive area roadways after a wintry blast that hit the area over the weekend started to thaw early this week.
Any time we get this pattern of freezing and thawing and rain and wind it s all a recipe for slides, and we certainly have a lot of spots in the Portland area for slides. When you have roads that are right beneath hillsides and you have a lot of rocks and trees. These are things Mother Nature brings down, said ODOT Spokesman Don Hamilton.
The large rock slide shutting down eastbound lanes of Interstate 84 is the biggest slide so far, but there were other leading up to it this week.
Hamilton said there are four areas that slide hazards are highest.
There are on Highway 26 from downtown Portland to the Oregon Zoo exit, Highway 30 north of Portland, 99E south of Oregon City, and the Columbia Gorge.
ODOT does mitigation projects. The most recently completed stabilized the hillside along the Jefferson onramp to westbound Highway 26.
Hamilton said crews are watching for problems in those areas and other places slides could happen.
They look for little trickles of rock that may have come down, for trees that have come down. They look for the signs of the little things because those are often the things that will lead to bigger problems, he said.