HTNB Corp | SR 99 North Portal


Title: Urban Gateways: North Portal, SR99 Tunnel

Project: SR 99 Tunnel Project

Firm: HNTB Corporation

Summary: The gateway sits at the northern end of the city center, highlighting the arrival downtown from the north. The strong features of the ramps and north portal wall are emphasized with plant material from the rivers and streams of Washington. Harrison Street provides a slower, pedestrian scale experience. A small plaza above the portal provides view opportunities north to Lake Union, while a larger plaza sits adjacent to the operations building. Sitting directly above the tunnel, the North Operations Building serves as a prominent beacon with the bold “safety yellow” ventilation stacks.