Key System
IER trains from Berkeley no longer stopped at 16th Street when railroad service over the Bay Bridge opened in January 15, 1939, as the junction from those lines to the bridge was north of the station. When the IER folded in July 1941, portions of some lines were sold to the competing Key System for use by their transbay trains; however, the Key System only served the station with a surface streetcar line on 16th Street, and did not use the elevated platforms.