In December 1962, the Lake Washington Ship Canal Bridge (the part of Interstate 5 that connects Seattle's University District to Capitol Hill) opens to traffic. It is at the time the largest bridge of its kind ever built in the Northwest. The giant 4,429-foot bridge was completed in the fall of 1961, more than a year before the freeway of which it formed a part was completed. During its first year, the bridge towered silently over the neighborhoods like a monument to the steel truss bridge.
The first contract made for what was called the Seattle Freeway (now part of Interstate 5) was let in 1958 for constructing the bridge's piers. There were many delays and controversies in completing the project, including labor disputes, a time-consuming process of relocating power lines, and a controversy over the downtown lid part of the project.
It is a steel truss double-deck bridge, which carries eight lanes of traffic on the upper deck and four reversible lanes of traffic on the lower deck. The truss design is the Warren truss, composed of diagonals placed alternatively in tension and compression. Twelve painters with nerves of steel painted the bridge by hand. They applied 10,000 gallons of undercoat and linseed oil topcoat.