Friday, April 15, 2016

Snoqualmie Pass closures highest in four years

By Summer Derrey

If it feels like Snoqualmie Pass was closed to traffic more than usual this past winter, well, it was. Some record snowfall leading to avalanche control, combined with a large number of collisions led to the pass being closed for almost 200 hours.

Photo of snow plow and traffic on I-90 Snoqualmie Pass
Snoqualmie Pass was closed to traffic for almost 200 hours during the 2015/16 winter season
as workers and drivers battled some record snowfall.

Here's a look at the 2015 – 2016 Snoqualmie Pass winter closures by-the-numbers.

  • 121 hours closed
  • 62 %
Avalanche Control Closures
  • 76 hours closed
  • 38 %
  • 197 hours closed
  • 100 %

Of the above closures, eastbound lanes were closed 101 hours and westbound lanes 96 hours.

December 1 - 31
  • 193 inches of snow
  • 42 %
December 18 - 24
  • 112 inches of snow
  • 58 %

The pass had record breaking snowfall this season with 193 inches in December. The fourth week of December was the snowiest 7-day period in Snoqualmie Pass history with a record snowfall of 112 inches.

December 18 – 24
  • 75 hours closed for collisions
  • 61 %
December 18 – 24
  • 101 hours of overall closures
  • 85 %

Sixty percent of the collision closure hours happened in the fourth week of December and 85 percent of overall winter closures occurred the same week.

December 23 - 24
  • 37 inches of snow
  • 19 %
Winter 2015 - 2016
  • 193 inches of snow
  • 81 %

Remember Christmas Eve? We do! The pass was closed for much of the day, stranding holiday travelers. Snoqualmie Pass received 37 inches of snow within 24 hours from December 23 to 24.

Photo of snow avalanche under I-90 at Snoqualmie Pass
While collisions accounted for the majority of Snoqualmie Pass closures, 193 inches of snowfall
in December led to lots of avalanche control work as well.

Two separate collisions were responsible for 21 hours of the 121 hours of collision closures. Both were tanker truck rollovers that created unsafe conditions on the road.  Another 15 hours of collision closures were due to the investigation of a multi-vehicle fatality collision.

With Work Zone Awareness week upon us, now's as good a time as any to remember that driving for conditions is vitally important, both for workers and for everyone on the road. The majority of these recorded collisions on Snoqualmie could be prevented by adhering to speed reduction, using proper traction devices, and obeying WSDOT's advanced warnings.

This is a mountain pass and weather conditions change rapidly. We do our best to mitigate those hazards by installing rock fencing, patrolling the highways 24/7, clearing snow and closing the highway when high avalanche danger exists.

But we need drivers to help by slowing down, driving for conditions and always focusing on the road. It's like our crews up on the mountain say "We can do just about everything short of driving your car for you."