The Key System, a privately held company, provided transit in the East Bay from 1903 until being sold to the public entity AC Transit in 1960.

The first cable car appeared in the East Bay in 1886  on the arterial road, San Pablo. Electric street cars followed in 1891, knitting togther Berkeley and Oakland with intercity rail lines. By 1893, the street cars were being consolidated into the Key System by Francis Marion “Borax” Smith. Although the conglomeration of tracks already served the East Bay from Richmond to San Leandro, Smith furthered the service by building a pier that pulled a track out into the bay, with the final 3 mile leg of the transbay service being completed by ferry. This jutting feature into the bay along with the maze of tracks on land resembled an old fashioned key in plan view, thus giving the Key System its name.

By 1924 the Key System had reached a peak of 18 million riders and was typical of integral rail systems in cities across America. However, by the 1930s street cars were already losing major ground to automobiles. The transbay bridge was primed for car and truck crossing in 1936, but did not accomodate rail for another two years. Locals already calibrating to the speed of the auto era, were abandoning the leisurely street car-and-ferry crossing. In another blow to the Key System, tolls at bridge crossings dropped drastically, further driving up competition from auto commuters.

Although the lean war years did temporarily provide a second wind for the mass transit system, the system was beginning to age and infrastructural funds were not ready at hand. With the suburban boom that followed the end of WWII, transit began to decentralize. National City Lines backed by oil and tire companies began to buy up ailing rails across the country and replace them with bus service. In the East Bay, all electric street car lines, save the transbay route had been replaced by buses by 1948.

In 1956 voters approved the establishment of the publicly run Alameda Contra Costa Transit District. AC Transit bought out the nearly bankrupt Key System in 1960.

Credits: All information was gathered from the AC Transit website, and “The Rise and Fall of the Key System“, a slideshow presented at AC Transit Transbay Taskforce November 10, 2009 by Will Sparger.

For a good source of online historical photos of the Key System, click here. Take a trip across the historic Key System rails in a video here.