Once upon a time, the streets were chaotic and dangerous. There were no rules or regulations in place to guide the flow of traffic, which led to frequent accidents and congestion. However, in the late 19th century, an inventor named J.P. Knight saw an opportunity to change all of that.
In 1868, Knight created a gas-powered traffic signal that he installed at the intersection of Bridge Street and Great George Street in London. This signal consisted of two arms that could be raised or lowered by a police officer, allowing traffic to flow in different directions. While it was an improvement over nothing, this system was far from perfect. The arms often got stuck or malfunctioned, leading to confusion and accidents.
It wasn’t until 1912 that the first electric traffic signal was invented by a police officer named Lester Wire. This signal, which was installed in Salt Lake City, Utah, used red and green lights to control traffic flow. However, this system also had its flaws, as it required an operator to manually change the lights.
In 1920, a Detroit police officer named William Potts created the first automatic traffic signal. Potts used a system of four-way lights that used a timer to control traffic flow. This invention was revolutionary, as it allowed for more consistent and predictable traffic patterns.
Over the years, traffic signals continued to evolve and improve. In the 1950s, the first yellow caution light was introduced, providing drivers with a warning that the light was about to change. In the 1970s, sensors were added to traffic signals, allowing them to detect the presence of cars and adjust the timing of the lights accordingly.
Today, traffic signals are a ubiquitous part of modern life, found on every street corner and intersection. They provide a vital service, helping to keep drivers and pedestrians safe and organized. While the history of traffic signals has been a long and winding road, their continued evolution is a testament to human ingenuity and the ongoing quest for safety and efficiency on our roads.