The San Francisco–Oakland Bay Bridge is a series of bridges across San Francisco Bay in the U.S. state of California. It is part of Interstate 80 in California.
It has two spans over water. The western span is a suspension bridge. The eastern span is a self-anchored suspension bridge. The eastern span used to be a cantilever bridge but it was removed once the new bridge opened. The cantilever span was destroyed in the 1989 Loma Prieta Earthquake, which is one of the reasons why the Eastern span was replaced.
The western span is a double suspension bridge with two decks. Westbound traffic is carried on the upper deck and eastbound on the lower deck. The new east span is a single deck with the eastbound and westbound lanes on each side. It is the world's widest bridge.