The Alaskan Way Viaduct was built in three phases in 1949 through 1953 and opened on April 4, 1953. It features a double-decked elevated section of State Route 99 that runs along the Elliott Bay waterfront in the industrial district and downtown of Seattle. It is the smaller of the two major north–south traffic corridors through Seattle (the other being Interstate 5), carrying up to 110,000 vehicles per day. The viaduct runs above the surface street, Alaskan Way, from S.