OK, well, they’re not there any more but the first traffic lights erected anywhere in the world were placed on the north-east corner of Parliament Square in Westminster on 9th December, 1868.

The location at the intersection of Great George, Parliament and Bridge Streets outside the Houses of Parliament wasn’t chosen by random – there had been several traffic accidents at the congested site.

The seven metre tall lights, which were operated by a police constable, were based on railway signals – in fact they had been invented by a railway engineer, John Peake Knight of Nottingham. A City of Westminster plaque commemorates him close to the site.

The structure (pictured above in a police notice of which apparently some 10,000 copies were made) featured three semaphore arms which were lowered to an angle (signalling go or caution) or raised to horizontal (signalling stop). There was also gas-powered light for use at night – it changed from green (go or caution) and red (stop).

They didn’t last too long – many drivers didn’t recognise what the signals meant, others ignored them and there were frequent problems including a gas leak at the base which led to an explosion injuring the policeman operating them at the time. They were removed the following year.

The first electric lights, meanwhile, didn’t arrive in the capital until after their invention in the US where the first were  installed in Cleveland, Ohio, in 1914. In London it wasn’t until 1926 that the first electric lights were installed, this time at the intersection of Piccadilly and St James’s Street.

The first vehicle-activated lights came some seven years later and were installed at the corner of Gracechurch Street and Cornhill in the City.

PICTURE: Leonard Bentley/Creative Commons