On December 9, 1868, the first traffic lights were installed outside the Palace of Westminster (House of Parliament).

Traffic Lights For the Railroad

Traffic lights were invented by J P Knight, a railway signaling engineer. They were a response to the chaotic junction at the Parliament, which had just months before caused separate accidents where 2 MPs were injured and a policeman killed.

The original traffic light looked similar to the way our current railway signals look today—there were two mobile signs that pivoted when a lever was pulled. The operators had to wave semaphore arms with green and red lamps and ran on hot gas.

When the gas was at 45, the light turned green, allowing the cars to move cautiously. When it was raised, it turned red, making the cars stop to let pedestrians cross.

Unfortunately, the device was far from effective and was only operable during the night when the lights were visible.  

A Short-Lived Invention

The initial reception was mixed because some people did not understand the symbols, while others ignored them altogether.

However, the invention came to a halt when the new traffic light blew up in an unexpected accident and killed a police officer. After the incident, production was stopped until the era of combustion engines came. It wasn’t until better energy sources were discovered that the idea of traffic lights was revisited.