 From there, motorists would drive onto a ferry boat which would cross the Golden Gate to Sausalito, where they would drive off the ferry directly onto the main street of Sausalito, which was signed for US 101 once again.The US 101E designation was removed by the 1940s and became SR 17 (later I-880 and I-580) between San Jose and Santa Cruz.As the Bayshore Freeway was built along the east side of the San Francisco peninsula in the early 1950s, old US 101 along the El Camino Real was posted as US 101 Alternate or US 101A, and the freeway was marked US 101 Bypass or US 101B.