Today marks the centenary of the first three-light (red, amber, green) traffic lights being introduced into the UK. Not the very first traffic lights, as the first was installed outside Parliament in December 1868, but it was more of a converted railway signal and was mainly to stop traffic for a pedestrian crossing. Although semaphore-style traffic lights were used in other countries, the Parliament episode rather put people off them in the UK. So the very first network of traffic lights was, in effect, a railway junction. Initially, the traffic lights were only used during the daytime, as there wasn’t enough road traffic at night to justify the effort.