The San Mateo—Hayward Bridge across San Francisco Bay is a 11.3 km long structure. It consists of three sections a 0.1 km approach, a 3.2 km main span across the shipping channel and a 8.1 km trestle structure that ties it to the east bank. In 1993 the bridge was examined and found to require retrofit for earthquake safety. The structure is located approximately midway between the San Andreas and Hayward faults.