First traffic lights

Semaphore-type traffic signals were set up in Parliament Square, London in 1868 with red and green gas lamps for night use. It was not an offence to disobey traffic signals until assent was given to the 1930 Road Traffic Act. Traffic lights were introduced in Great Britain with a one-day trial in Wolverhampton on 11 February 1928. They were first permanently operated in Leeds, W. Yorks, UK, on 16 March 1928 and in Edinburgh, Scotland, on 19 March 1928. The first vehicle-actuated lights were installed by Plessey at the Cornhill-Gracechurch junction, City of London in April 1932.