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History of the Modern Traffic Signal

August 22, 2018

The traffic signal is a part of many people’s daily lives, yet people rarely stop to think about its impact. Think of all the lives it has saved and what the world would be like without it. Here’s a brief history of traffic signals, which have now been directing traffic for over a century.

Early Traffic Signals

Throughout the 19th century, the railroad industry used signaling systems with gas-powered lights to warn onlookers about approaching trains. Back in the early 1900s, cars were beginning to emerge but did not dominate the streets yet. This was an era in which horses, carriages, pedestrians, and automobiles shared the road. The first electric traffic signal appeared in Cleveland in 1914. By the following decade, these signs were common across America.

A few years later, the first “no left turn” sign was installed in Buffalo. A few other events in that era cloud the question as to who invented the first traffic signal. The modern traffic light system reflects the 1918 patent awarded to James Hoge, who developed a “Municipal Traffic Control System.” His system was based on four sets of red and green lights, each mounted on a pole at the corner of the intersection.

Due to the variety of traffic speeds converging, collisions were common in the early days of cars. In 1920, New York commissioner of traffic Dr. John A. Harriss came up with a solution to reduce accidents. He designed a basic two-light signal encased in a wooden box supported by a steel frame. Ironically, green meant “stop” while the white or clear light meant “go.” Early traffic lights used a range of colors until the end of the 1920s, when it had become established that green meant go and red meant stop.

Evolution of Traffic Signals

The automated traffic signal began to appear in major U.S. cities beginning in the 1920s, as lights changed at fixed time intervals. The concept of three lights, with yellow in between red and green, also started in the 1920s, appearing first in Detroit. The sixties ushered in computerized traffic lights. Eventually, monitoring systems were put in place to help determine when it was necessary to change lights.

One of the key developments of the past few decades has been the countdown timer, which was introduced in the 1990s. This timer helps pedestrians decide if they have enough time to cross the street in the remaining seconds. As traffic continues to increase, it’s likely that new innovations will continue to transform the possibilities of traffic signs.

The key to the evolution of traffic signals has been envisioning ways to make traffic safer. Smart technology allows for sensors to monitor traffic, which is integrating with modern traffic signal systems. For more information about traffic signage, call Zumar at our Arizona, California, or Washington location.

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