I-90 Keechelus Dam to Stampede Pass Phase 2A
The 2A project improves 2.5 miles of I-90 on Snoqualmie Pass from the Keechelus Dam vicinity to the Stampede Pass Interchange (MP 59.50 to MP 62.00) by widening the existing four-lane highway to six lanes. Construction also includes an illuminated chain-up area on the westbound lanes, new culverts at Unnamed Creek and Townsend Creek, a wildlife overcrossing at the Price Creek Rest Area Vicinity, hydraulic connectivity zones at two locations, concrete barrier and guardrail, Intelligent Transportation Systems (ITS), additional mitigation sites at the Price Creek Mitigation Site, and new bridges at Unnamed Creek, Price Creek, and Noble Creek.
The project increases capacity and improves safety by adding a new lane in each direction, replacing concrete pavement, stabilizing rock slopes, building wildlife crossings, straightening the roadway, and adding a new chain-up area. The wildlife crossing is located in the historic migration path to Keechelus Lake and will accommodate animals such as elk, deer, and black bear—while significantly decreasing wildlife collisions with traffic.
This project adjoins the east end of Atkinson's current Phase 1C contract where we are widening three miles of I-90 from four to six lanes and building side-by-side elevated avalanche bridges. Atkinson runs one comprehensive traffic control program for the two projects out of our existing office to maximize coordination and reduce costs for WSDOT.