Numbers, please! Three light signals for worldwide traffic control
Traffic lights originated in Victorian London, which sought to regulate traffic chaos following two fatal accidents involving British MPs.
The first traffic light in the world was put into operation on December 10, 1868, in London at the intersection of Great George Street and Bridge Street, as the newly elected British Parliament convened for its first session. It protected the Lords and MPs who had to cross a dangerous street on foot. It was constructed by railway engineer and inventor John Peake Knight, based on the model of railway signals.
When the two semaphores were raised and the red light was on, traffic had to stop and pedestrians could cross the intersection. At a 45-degree angle, traffic was only allowed to enter the intersection slowly with extreme caution. With lowered arms and green, the coachmen had free passage. The approximately 10-meter-high traffic light was operated by a traffic policeman, who was seriously injured in early January 1869 when the gas line of the traffic light system exploded. The traffic light was soon taken out of service thereafter.
Largest City in the World with Unregulated Traffic Chaos
In the mid-19th century, London, with four million inhabitants, was the largest city in the world with the largest port. And the city had a serious traffic problem, as the statistics on traffic accidents showed: in 1866, there were 1102 deaths and 1334 injuries. Among them were two MPs who were on their way to Parliament.
A commission was appointed to find a solution to the traffic issue. There was no shortage of suggestions: delivery vehicles should only be allowed in the city center during off-peak hours. Lighting should be prescribed, especially for the fast taxicabs. A driving ban around Parliament was also discussed, because after all, it was also forbidden to die in Parliament—that would have resulted in an expensive state funeral. Finally, they agreed on the suggestion by John Peake Knight to build a traffic light and test it at a busy intersection before introducing it throughout the city.
The railway engineer had already done something for traffic safety. He was the one who introduced the compressed air brake of American inventor Westinghouse in Great Britain and dealt with signaling for train drivers. The traffic light he designed was 7.30 meters high, and the semaphores were another 2.45 meters long. A policeman operated the small tower with a cable pull and lamp switch. The first alternating light signal system, as the traffic light is officially called, was built by Saxby & Farmer and was installed in front of Parliament.
Satisfied Citizens—Annoyed Taxi Drivers
The London Times reported on pleasantly surprised pedestrians who could cross the intersection, but also that coachmen ignored the system. Especially the London Cabbies complained and felt hindered in their fast passenger transport.
(Image: Bundesarchiv, Bild 102-01702 / CC-BY-SA 3.0)
After three weeks, a traffic policeman was seriously injured when he wanted to turn off the gas for the lamps in the evening and the line exploded. After some repair attempts, the traffic light was finally shut down, although British Home Secretary Henry Bruce reported in Parliament that his police officers raved about the traffic light. After all, they no longer had to stand at the intersection.
In the end, the first traffic light was replaced by another innovation. A pedestrian tunnel allowed safe access to Parliament. In 1871, The Times printed a letter to the editor in which the traffic light complained about its fate and implored the parliamentarians to bring it back to life. “I want to raise my arms again and impress the art critics with my being.”
It was all to no avail. A year later, the traffic light resignedly complained in another letter to the editor that it was no longer noticed and would at most frighten the children. The traffic light asked for its removal and a decent burial. Shortly thereafter, it was dismantled and scrapped.
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Dispute over color arrangement of Traffic Signals
It would take decades until the traffic light was reinvented in 1912 with the motor cabs by police officer Lester Wire in Salt Lake City. Wire's electric traffic light hung on wires above an intersection and was operated by a police officer who sat in a cabin above the traffic at the intersection. The introduction of traffic lights caused some problems in the USA. In cities where Irish immigrants formed the majority, they demanded that the Irish green must be above the red of the British occupiers.
In tough negotiations, future US President Herbert Hoover, to the relief of colorblind people, ensured that red always shines at the top and green always at the bottom, a proposal that was adopted by the League of Nations in 1931. In Germany, Josef Heuer, whose sons were colorblind, developed the Heuer traffic light, which hung above an intersection, for this reason.
(Image: CC BY-SA 4.0, 運動会プロテインパワー)
Meanwhile, the traffic light had begun its triumphant march around the world. From the USA, the traffic light returned to Europe. In Paris and Hamburg, the first traffic light was installed in 1922, in Berlin in 1924, and in London in 1925. With 6,252 installations in 2015, London reached a top position before the number of traffic lights was reduced in 2017 in the course of the pollution toll. In Japan, the first traffic light was put into operation in 1930 in Tokyo, with the curious circumstance that in Japanese, green can also mean blue, and the traffic lights with a very blue green illuminate when the crossing is clear. However, it took a while for the traffic light to be internationally standardized. This process was completed with the International Rules on Road Signals [PDF] in 2006.
With the “Green Wave,” invented by German emigrant Dietrich Prinz in Manchester, computers first interfered with everyday traffic light operations in the late 1950s. Today, it is, as is well known, the all-determining AI that is supposed to ensure orderly coexistence. Of all places, in Hamburg, the secret capital of construction sites and detours, the Google project Greenlight, with intelligent traffic lights, is intended to make traffic more emission-friendly. An expansion of public transport along with green requests for buses and Velo Flow for cyclists would be alternatively feasible.
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