It’s the centenary of the modern three-colour traffic light

Today marks the centenary of the first three-light (red, amber, green) traffic lights being introduced into the UK.
The traffic light artwork at Canary Wharf
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.
It also only lasted barely a month before a gas leak exploded it. Which didn’t really make people keen to try again.
Although semapho