Most people walk right past the Bay Bridge spread out in front of you, heading for its more photogenic sibling to the west, yet it carries more traffic than any other bridge in the United States. The San Francisco-Oakland Bay Bridge was completed on November 12, 1936, six months before the Golden Gate Bridge opened, and it is by almost every engineering measure the larger achievement: 4.5 miles long from anchorage to anchorage, consisting of two separate bridge structures — a double suspension span from San Francisco to Yerba Buena Island, and a cantilever and truss span from Yerba Buena to Oakland. More than 100,000 vehicles cross it every day.
The bridge passes through Yerba Buena Island, a natural island in the middle of the bay, and Treasure Island, a flat artificial island built from bay fill for the 1939 Golden Gate International Exposition, another world's fair San Francisco staged in the shadow of gathering war clouds in Europe. After the fair, Treasure Island became a Naval Station that operated until 1996; it is now being developed as a residential neighborhood. The Bay Bridge's distinctive LED light installation — 25,000 white lights installed by artist Leo Villareal in 2013 — runs every night from dusk to 2 a.m., tracing animated patterns across the cables of the western span.
From this viewpoint on a clear night, both bridges light the sky above the black water of the bay.