Learn about the first traffic light and how it transformed traffic safety.
On December 10, 1868, the first traffic light was erected on a 22-foot-high (6.7-meter) cast-iron pillar at the corner of Bridge Street and New Palace Yard off Parliament Square in London, England.
Invented by J.P. Knight, a railway signalling engineer, the light was a revolving lantern illuminated by gas, with red and green signals. It was turned by hand using a lever at the base of the pole.
Cleveland, Ohio installed an electric traffic signal at Euclid Avenue and 105th Street on August 5, 1914. It had red and green lights with a warning buzzer as the color changed.
Around 1913, Detroit, Michigan used a system of manually-operated semaphores. Eventually the semaphores were fitted with colored lanterns for night traffic.
New York City installed the first three-color light signals in 1918; these signals were still operated manually.