A (Crash) Course History of Traffic Signals

Today’s traffic lights are state-of-the-art. Some of them are even solar-powered to maximize functionality while minimizing energy consumption. 

Despite the fact that traffic lights play an important part in road safety, they are often not taken into consideration. If there were no traffic lights, we would not be able to travel the roads without the possibility of an accident.

Traffic signals play such a vital role in how we operate as a society that running a red light’s impact on car insurance causes drivers to follow the laws of the road.

With the amount of traffic we have today, it would be close to impossible to navigate the road without an accident. About 40% of all collisions are expected to occur at intersections where traffic signals are located.

So it is painfully clear that automobile accidents could be much worse if traffic signals did not evolve into what we know them as today. 

According to the National Highway Traffic Safety Administration, it was announced that traffic fatalities in 2010 were at an all-time low since 1949, despite the number of miles Americans drove during that year. In fact, from 2018 to 2019, fatalities in motor vehicle traffic crashes decreased by around 2%.

Yet, driving laws, car safety features, and other vehicle safety programs were all implemented from the main idea behind the introduction of traffic lights: to facilitate the safe movement of cars, avoiding collisions. 

So, whether drivers realize it or not, the creation of traffic signals jump-started decades of cautionary traffic enhancements that save millions of lives each year.

The Beginning of Traffic Lights (the 1860’s)

Right now we are used to the automatic traffic signals that are operated by electricity. However, before we had universal access to electricity, traffic lamps and other roadside illumination such as street lights were fueled by gas and flame.

Pioneering traffic signals originally appeared in London in the 1860s. On the recommendation from British railway engineer J.P. Knight, the first gas-lit traffic lights were installed outside the houses of Parliament.

The traffic signals were intended to regulate horse carriage traffic.

During the day and night, they were manually operated by police officers. The officers used green gas lights during the daytime and red gas lights at night to signal stops.

The First Traffic Light

The original traffic signals were traded out by a control device that was a revolving four-sided metal box on top of a glass display with the word “Stop” painted in red and the word “Go” painted in white. This device was first placed on top of a tower in Paris at the Rue Montmartre and Grande Boulevard.

Eventually, the lights became a safety threat because gas leakage would cause them to explode, injuring the police officers who operated them. 

Following the London traffic light explosions, efforts to automate traffic signals came to a halt. There were no more traffic lights in London until 1929. In the U.S., it took 40 years for vehicles clogging city streets to push for the installation of traffic lights.

In the early 1900s, police officers in the U.S. usually controlled traffic manually using a mixture of hand signals from towers that had a clear view of traffic. However, red and green gas-powered lamps were being used in some locations.

The First Electric Traffic Lights

One of the first electric traffic lights appeared in the U.S. in 1914. Lester Wire, an American police officer, invented the first electronic traffic light when vehicle traffic soared. It was first placed on August 5, 1914, at the intersection of 105th and Euclid avenues in Cleveland, Ohio.

An officer worked the four-sided electric traffic lightbox, which was elevated on a 10-foot pole and resembled a birdhouse. To turn between the dipped red and green lights, the officer would toggle a switch.

Electricity and Crowding Cities

When cities and traffic increased in size, so did the battle to resolve increasing traffic issues, like distracted driving causing car accidents. Semaphores were the earliest traffic signs. Semaphores are towers with rotating arms that warn traffic to halt or proceed. 

Those devices were either manual or automatic and there was no unified design. As the need for traffic control emerged, various models were developed and implemented in cities.

Automated signals appeared in Chicago before Lester Wire, an exhausted traffic signal operator, created the first manually controlled electric signal in Ohio.

Automated traffic signs were first used in Chicago in 1910. They didn’t light up, but they did create simple signs for traffic to “stop” or “proceed” per the labeled arms.

Though the traffic lights in Ohio and Chicago both used words to signal drivers, the words on the Ohio device were no longer written on arms that raised and fell. Lester Wire’s device used the words “stop” and “move” on posts that lit upon each of four corners around an intersection.

The dangers associated with officers standing in the center of an intersection to change the traffic signals decreased since they now could stand to the corner with a switch.

In 1917, a red and green electric traffic light system that could be controlled automatically or manually was introduced in San Francisco.

The Evolution of Automatic Traffic Lights 

The evolution of traffic light signals was kicked off with the creation of Motor City in the 1900s. Detroit was known as a motor city because the Ford Motor Company was founded there, with other motor companies following. 

Ford made automobiles more available to the general public by establishing larger-scale factory manufacturing. This change in production made automobiles readily available to everyone instead of only the elite class. Allowing more people access to cars meant finding cheap car insurance soon became necessary.

The uproar in automobile manufacturing and selling pushed along the evolution of automatic traffic signals. 

The streets were crowded with new vehicles, as well as delivery wagons, motorcycles, horse-drawn carriages, streetcars, and busy crowds. The launch of the yellow light assisted in reducing deaths caused by running red lights and increasing driver safety.

By the mid-20th century, computers had been introduced, and the evolution of traffic lights advanced even further. 

Computerized tracking allowed lights to switch more quickly and accurately, as opposed to using microphones that could detect sounds from upcoming traffic. Computerized tracking was beneficial for drivers and traffic pattern monitoring and management in emergency situations.

Around the year 2000, computers had improved to the point where traffic lights were more digitized. Countdown timers, for example, helped drivers to help gauge whether they could safely cross an intersection before the light turns red.

The Meaning of Colored Traffic Lights

Though people who operate vehicles universally understand what each colored traffic light means, some states use different signals for different purposes. With driving laws adjusting for smart cars, traffic lights have adjusted as well.

Universally, green means go, yellow means slow down, and red means stop, but it is still best to check the local light and signal purposes because each state may have varying significance for each symbol.

For example, in certain states, red arrows indicate that you cannot turn right on a red. In these situations, the only way you can make the turn is when the green arrow appears. However, in the other states, you can take a right on a red arrow after a full stop.

The Bottom Line on Traffic Lights

The definition of traffic lights is generally clear around the world. Green indicates that it is possible to continue, while still driving cautiously. Yellow signifies being cautious and yielding. Red denotes a hazard and to stop. 

It’s true, traffic signals will continue to evolve as long as technology continues to evolve. So you should aim to drive defensively and safely while continuing to follow the evolving traffic signals at all times.