State Route 99 Tunnel

Seattle, Washington | Infrastructure & Public Works

Hermanson played a crucial role in the State Route 99 Tunnel project in Seattle. Handling the HVAC and Plan & Spec scope, we contributed to the construction of this 2-mile, double-decker tunnel, replacing the Alaskan Way Viaduct. Our involvement, spanning from the groundbreaking in July 2013 to the tunnel's opening on February 4, 2019, showcases our capabilities with major infrastructure projects in the heart of the city.

Completed in 2019