Project Info:

Location: Snohomish County, Washington

Role: Prime

Owner: Washington State Department of Transportation

Client: Washington State Department of Transportation

Construction Cost: $80,000,000


  • Alternatives Development and Analysis
  • Interchange Design
  • Traffic/Transportation Analysis
  • Highway/Roadway Design
  • Cost Estimate Development

Heavy congestion at the SR 522/Paradise Lake Road intersection would frequently spill over onto side streets, and drivers would often use the highway to find ways around bottlenecks. To improve functionality, the Washington Department of Transportation (WSDOT) hired Lochner to develop conceptual design alternatives for a new interchange at the SR 522/Paradise Lake Road intersection. The goal of the new interchange was to increase traffic flow, add capacity for freight traffic and commuters, improve travel times, and decrease congestion as well as the risk of rear-end collisions during stop-and-go conditions.

In addition to developing design alternatives, Lochner was responsible for coordinating with WSDOT, Snohomish County, the industrial and commercial facilities in the nearby business park, and local residents to achieve a consensus on the preferred alternative. Once consensus was reached, the selected conceptual design was advanced to a design-build procurement.