Key Rail System - Definition and Overview

The Key System Railway (or Key System Interurban) was a light-rail system that served the eastern San Francisco Bay Area from the 1900s through the 1950s. It was the eastern counterpart to the San Francisco Municipal Railway or “Muni” streetcar system. Much of the current service area is now covered by the modern day Bay Area Rapid Transit (BART) System.

The system was a consolidation of several smaller streetcar lines assembled in the early 1900s by Frank “Borax” Smith, an entrepreneur who made a fortune in his namesake mineral. At its height during the 1940s the Key System had over 66 miles of track that connected the communities of Richmond, Albany, Berkeley, Oakland, and San Leandro to San Francisco. On a map the routes looked roughly like an old-fashioned key, with three “handle loops” that covered the East Bay cities and a “shaft” that extended westward toward San Francisco; thus the anecdotal source of the system’s name.

The initial connection across the Bay to San Francisco was through a causeway that extended from Emeryville westward 16,000 feet (4,900 meters) to a ferry terminal near Treasure Island. The Key System operated a system of ferries that made the final short connection to San Francisco. After its completion in 1936, San Francisco-Oakland Bay Bridge had a dual track on its lower deck that directly connected the Key System to the Transbay Terminal in San Francisco’s downtown.

The system was eventually dismantled in 1958 after a General Motors subsidiary purchased the system (see General Motors streetcar conspiracy). State planners anxious to embrace California’s postwar love for the automobile also pushed to have the track across the Bay Bridge and street right-of-ways removed to increase highway and street capacity.