The first traffic lights were installed on 10 December 1868 outside the British Houses of Parliament in London to control the traffic in Bridge Street, Great George Street and Parliament Street. They were gas lit. Those lights were constructed by the railway signal engineers of Saxby & Farmer. They were operated by a police constable. The gas lantern was manually turned with a lever. But they didn’t last long. After the light exploded on 2 January 1869, as a result of a leak in one of the gas lines, injuring the policeman, this concept was abandoned. The first electric traffic light was developed in 1912 by Lester Wire, an American policeman of Salt Lake City, Utah. On 5 August 1914, the American Traffic Signal Company installed the first traffic signal system in Cleveland, Ohio. It had red and green lights and a buzzer. The first four-way, three-color traffic light was created by police officer William Potts in Detroit, Michigan in 1920. The oldest working traffic light in the US that was used from 1932 to 1982 now rests in a museum in Ashville, Ohio.