<Tr> <Td> </Td> <Td> This article may be too long to read and navigate comfortably . Please consider splitting content into sub-articles, condensing it, or adding or removing subheadings . (March 2018) </Td> </Tr> <P> Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights, stop lights, robots (in South Africa and most of Africa), and traffic control signals (in technical parlance), are signalling devices positioned at road intersections, pedestrian crossings, and other locations to control flows of traffic . </P> <P> The world's first traffic light was short lived . It was a manually operated gas - lit signal installed in London in December 1868 . It exploded less than a month after it was implemented, injuring its policeman operator . Traffic control started to seem necessary in the late 1890s and Earnest Sirrine from Chicago patented the first automated traffic control system in 1910 . It used the words "STOP" and "PROCEED", although neither word lit up . </P> <P> Traffic lights alternate the right of way accorded to users by displaying lights of a standard colour (red, amber (yellow), and green) following a universal colour code . In the typical sequence of colour phases: </P>

When was the first manual traffic signal invented