Rock Slides Concern Highway 3 Travelers

The in basket: The fatal rock fall in Snoqualmie Pass last fall prompted Aimee Warthen of Bremerton to ask about the cliffs between Bremerton and Gorst on Highway 3.

“The southbound traffic travels precariously close to overhanging rocks,” she wrote. “As someone who travels this road most days of the week, I was wondering if we could experience our own tragic rock slide someday along this route. Do you know who monitors the rocks and how often they are checked for stability?”

The in basket: The fatal rock fall in Snoqualmie Pass last fall prompted Aimee Warthen of Bremerton to ask about the cliffs between Bremerton and Gorst on Highway 3.

“The southbound traffic travels precariously close to overhanging rocks,” she wrote. “As someone who travels this road most days of the week, I was wondering if we could experience our own tragic rock slide someday along this route. Do you know who monitors the rocks and how often they are checked for stability?”

It was the first inquiry of its kind since Don Green of Allyn wrote in 1998 to say “some of the rocks atop the cliff beside Highway 3 near Gorst look shaky,”

Media coverage of the Snoqualmie Pass fatalities and a subsequent rock fall there mentioned a state rating system for unstable slopes. I wondered where the Highway 3 cliffs were in that ranking.

The out basket: It wasn’t tragic, but there was a rock fall on that stretch just this month. That’s a rarity there, according to Tom Badger, one of the six geotechnical employees of the state transportation department.

A few small- to medium-sized rocks came down near Windy Point on Jan. 7 and got around or over the concrete barrier on the shoulder. But they apparently didn’t reach the driving lanes.

Badger said that rock fall caused his division to realize that those cliffs had been omitted from the hazard rating system, on which problem slopes are graded on 11 criteria that create a numerical ranking ranging from 33 to 891. Any rated more than 350 are considered for reinforcement, with traffic volume and the cost of a closure factored in.

It must be a pretty flexible rating system because in just one day, the division calculated that the Highway 3 cliff they had overlooked rated a 327. Nothing substantial is planned for now, beyond a study of moving the concrete barrier a little closer to traffic.

The rating system isn’t just for cliffs. It’s also for unstable slopes, such as those across Sinclair Inlet on Highway 166.

Badger says there are 14 rated slopes between Gorst and Port Orchard. All that were rated between 350 and 400 have been repaired. The highest rated unrepaired slope, at 345, is just west of the Port Orchard Boulevard intersection.

The slope that came down Jan. 7 and blocked the road was in the low 200s, so the rating system isn’t foolproof. In fact, the place where three women were killed in Snoqualmie Pass rated less than 200, Badger said. The later rock fall on the east side of the pass was rated 375 and scheduled for work.

Send questions for the Road Warrior to reporter Travis Baker at tbaker@kitsapsun.com. Read his blog online at kitsapsun.com by clicking on the blog link.

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