The Richmond-San Rafael Bridge
Less well-known around the world than the iconic Golden Gate Bridge, and not even as well-known as the Oakland-San Francisco Bay Bridge, the Richmond-San Rafael Bridge is nonetheless one of the vital links over the waters of the Bay. The Richmond-San Rafael Bridge is the northernmost of the east-west crossings over San Francisco Bay, linking the East Bay at Richmond to San Rafael (home of the infamous San Quentin Prison) in Marin County. Construction was begun in 1952 and was completed in 1956.
The bridge is 5.5 miles (28.9 km) long. At the time it was built, it was one of the world's longest bridges. The bridge spans two principal ship channels and has two separate major spans, each of the cantilever type. In the interest of resistance to earthquakes, the portion connecting the major spans is lowered in elevation, giving the bridge a "roller coaster" appearance and so also the popular name of its style; the "roller coaster span". This appearance has also been referred to as a "bent coat hanger". After it was completed, many were disappointed by the aesthetics of the low budget bridge, especially when compared to the engineering and historical marvels of the neighboring Golden Gate Bridge and the Bay Bridge.
The seven Bay Area bridges carry about 130,000,000 vehicles a year.