Built in 1911, the Key System Building, which is also known as the Security Bank and Trust Building, stands on the corner of 11th Street and Broadway. The exterior of the building was designed by San Francisco architects Frederick H. Meyer and Walter Reed in the Beaux Arts Style. In 1910, the lot was sold by J. S. Myers to the Security Bank and Trust Company for $150,000 and in 1943, the building became the headquarters for the Key System transit line. The building is on the National Register of Historic Places and is also a designated Oakland Landmark.
The Key System was a mass transit company that operated in Oakland and around the state of California from 1903 until 1960 when it became AC Transit, a public agency. The Key System operated a mix of bus and streetcar lines, as well as commuter rail and bus services. During its height, the Key System utilised over 66 miles of track. The company came about at the turn of the 20th century when it consolidated a handful of streetcar lines. It began as the San Francisco, Oakland, and San Jose Railway in 1902 and services began a year later. The general manager of the company created a new form of map in the style of an old-fashioned key, with three handle loops covering the cities of Berkeley, Piedmont, and Oakland. This became known as the key route, and the company became known as Key System.
The Key System's famed commuter train system was dismantled in 1958 after many years of declining ridership. The last run was on April 20, 1958. In 1960, the newly formed publicly owned AC Transit took over the Key System's facilities.