09/04/2026
On September 3, 1959, the final phase of Seattle's Alaskan Way Viaduct officially opened to traffic, marking the completion of a massive infrastructure project that began a decade earlier. This southern extension linked up with the previously finished central portion (which opened in 1953) and the Battery Street Tunnel, fully establishing a 2.2-mile, double-decked elevated freeway along the city's waterfront. Originally built to carry U.S. Route 99, and later Highway 99, the viaduct provided a crucial, limited-access bypass that eased some traffic congestion on downtown Seattle's surface streets.
It served as one of the city's primary north-south transportation corridors for nearly 60 years until it was permanently closed in January 2019 and subsequently demolished to make way for a replacement tunnel following structural vulnerabilities exposed by the 2001 Nisqually earthquake.
📷 Alaskan Way Viaduct, ca 1959. WSDOT photograph.
📑 Brochure: Alaskan Way Viaduct, South Extension Opening, September 3, 1959.