A History of the Traffic Light and How it May Change Again! - DriveSafe Online® (2024)

Defensive driving means responding to the changing conditions of the road. It’s the best way to make sure you’re safe — and free of traffic fines.

However, there’s one aspect to driving that still seems to trip up many old and new drivers. And that’s timing your driving decisions to traffic lights.

In 2018, 846 people died in crashes that involved running a red light. Overall, about 56% of Americans admit to running red lights because they’re often caught in the transition between yellow and red.

The good news is that traffic lights, which have come a long way since their birth, are about to change to avoid these kinds of situations.

What Did We Use Before Traffic Lights?

Many people believe that traffic lights and the modern automobile go hand-in-hand. It makes sense — after all, it’s car drivers who need a way to drive safely, yield to others, and communicate with each other.

However, traffic lights are related to the rise of cities and the Industrial Revolution. Even as consumers were adopting automobiles as the preferred means of transportation, there were still plenty of individuals using horse-drawn carriages.

The sheer number of people in densely populated cities like London and New York became impossible to control.

Before the first traffic light installation in London, it was up to traffic police to direct and control transportation flow. They had to be mindful of carriages, cars, and pedestrians, giving each group clear instructions on how and when to proceed.

Nowadays, of course, using law enforcement officers for traffic duty is an emergency tactic. We only use these officials when a traffic light loses electricity, or the power grid is down.

What is the History Behind Traffic Lights?

The first traffic lights were a solution to overcrowding and speeding on streets, which caused major chaos, accidents, and even deaths in major cities.

In 1913, more than 4,000 people died in car-related crashes. Automobiles, carriages, bicyclists, trolleys, and pedestrians were all clamoring for space. Major roadways in U.S. cities couldn’t handle that kind of volume and speed.

A History of the Traffic Light and How it May Change Again! - DriveSafe Online® (1)

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Inevitably, confusion led to collisions. Even police officers blowing whistles or waving their arms at dangerous intersections didn’t help catch drivers’ attention. What fast-industrializing cities needed was a reliable and non-human system for safe driving and road-sharing.

Who Invented the First Traffic Light?

J.P. Knight, William Potts, Lester Wire, and Garrett Morgan are all names you might hear in relation to the invention of traffic signals. In one way or another, these men did contribute to the modern-day, electrical traffic light design.

They each improved on the design and use of the traffic signals in the early part of the 20th century:

  • December 8th, 1868 — J.P. Knight, a British railway engineer, proposed controlling the flow of horse carriages around the Houses of Parliament. These were gas-powered lights manually operated by a police officer, using semaphore arms. However, they were also a safety hazard as the gas-light would explode and injure nearby officers.
  • 1914 — Some sources say it was James Hoge, while others credit the world’s first electric stop light to an American policeman named Lester Wire. Regardless, the signals system tapped into the electricity lines of local “trollies” or trams. This was essentially the first municipal control system, installed at Euclid Avenue and East 105th Street in Cleveland, Ohio.
  • 1920 — Next, a Detroit police officer named William Potts introduced the first four-way and three-colored traffic lights. Detroit was the first American city to embrace this traffic light system.
  • 1923 — Garrett Morgan applied for and received a patent for the three-position electric traffic signal. He later sold this to the General Electric company for $40,000.

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There was one more traffic light innovation just around the corner. In 1928, an inventor named Charles Adler Jr. developed a “sonic” traffic light. Cars could pull up and honk their horns, which would “sonically” trigger a light change.

This was actually the final iteration of the traffic light, which we base all our modern traffic signals on today. In 1929, he perfected the traffic light system by adding the pedestrian push-button to allow pedestrians the right of way.

What are the Different Traffic Light Colors?

No matter where you go, from country to country, traffic lights mostly mean the same thing.

Sometimes, there’s an additional “blue” light you may see in some countries. In Japan, for example, some signals don’t have a green light. Instead, they feature a blue light, which means go. That’s because the Japanese word for “green” is blue.

Besides a few international exceptions, the main traffic light colors are usually the same — red, which means stop, the yellow sign for slow down or take caution, and green for go.

It wasn’t always this way. While you may think red is a natural color that indicates alarm or danger, that’s not why it was the natural choice for the “Stop” motion on a traffic light. Instead, traffic light designers chose this color because of its long wavelength. This means a driver can see a red stop light from much farther away than a yellow or green signal.

Despite this, in the 1900s, some stop lights were yellow. While yellow has a shorter wavelength than red, it’s also easier to see in the dark of night than red! However, once we developed reflective materials, cities resorted to a uniform red all across the world. Yellow became the designated “caution” color instead.

Here are a few well-known traffic signal indicators in the United States:

  • Red arrows in combination with green arrows — These usually indicate that you can only take a right turn on a green arrow. In some states, such as Illinois, Kansas, Louisiana, and Maryland, among others, you can take a right on a red arrow, but only when you come to a full stop first.
  • Flashing red — Come to a full stop at a four-way intersection, as you would with a stop sign.
  • Flashing yellow — This means to yield or take caution while driving.
  • Flashing yellow arrows — After seeing the protected green turn signal, you can take a turn after yielding to pedestrians and traffic.

Are Traffic Lights Going to Change in the U.S.?

Today, urban traffic lights are computerized. This allows smarter timing that adjusts itself based on the time of day or the needs of pedestrians who are crossing. We also have cameras and sensors that can detect the presence of cars, bikes, and pedestrians.

However, traffic light systems will change worldwide as the “Internet of Things” begins further to affect the way lights transition. For example, engineers can control traffic light systems so that they don’t turn red right as cars arrive or keep a car waiting at an intersection where there is no cross-traffic.

These are just a few examples of what the United States Department of Transportation calls responsive traffic signals. It estimates these systems could save as much as 10% of all motor fuel spent on our roads.

Conclusion

Traffic lights are such a standard for motion that even a child can tell you that red means “stop!” and green means “go!” However, it took years to create this instant recognition, as drivers’ behaviors evolved with traffic systems on the road.

One of the most effective ways to create good habits as a driver is to use a defensive driving course. With just a few hours of instruction, you’ll be able to make better decisions and choices while driving on the roads today. DriveSafe Online’s digital classroom means you never have to leave your home to master the most important signs and symbols on the road. Learn more about DriveSafe Online’s course options for insurance discounts and safe driving habits.

A History of the Traffic Light and How it May Change Again! - DriveSafe Online® (2024)

FAQs

How did the traffic light change over time? ›

Traffic lights haven't changed much in the U.S. over the years. Cleveland debuted what is considered the first “municipal traffic control system” in 1914, historian Megan Kate Nelson wrote for Smithsonian Magazine.

What impact did the traffic light have on society? ›

By 1930, all major American cities and many small towns had at least one electric traffic signal, and the innovation was spreading around the world. The simple device tamed the streets; motor vehicle fatality rates in the United States fell by more than 50 percent between 1914 and 1930.

What are the traffic light changes? ›

Red light: Stop. Red & amber lights: Prepare to go. Green light: Go, if the way is clear. Amber light: Stop, provided it's safe to do so.

How does a traffic light know when to change? ›

Active infrared sensors emit low-level infrared energy into a specific zone to detect vehicles. When that energy is interrupted by the presence of a vehicle, the sensor sends a pulse to the traffic signal to change the light.

What is the history of traffic lights? ›

History of Traffic Lights

The first traffic light was invented in 1868 by British railway engineer J.P. Knight. It consisted of a revolving gas lantern with red and green signals. However, it was not until the early 20th century that electric traffic lights were developed.

What happened with the first traffic light? ›

In 1912, the first electric traffic light was developed by Lester Wire, a policeman in Salt Lake City, Utah. It was installed by the American Traffic Signal Company on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio.

How do traffic lights help drivers? ›

Traffic signals are designed to ensure an orderly flow of traffic, provide an opportunity for pedestrians or vehicles to cross an intersection and help reduce the number of conflicts between vehicles entering intersections from different directions.

What are the negative effects of traffic lights? ›

Traffic control signals may have one or more of the following disadvantages:
  • Signals may increase delay – both overall intersection delay and/or specific movement delay.
  • Signals may encourage the use of alternate and/or less adequate routes by drivers wishing to avoid the signal.

What problems do traffic lights solve? ›

The primary function of any traffic signal is to assign right of way to conflicting movements of traffic at an intersection, and it does this by permitting conflicting streams of traffic to share the same intersection by means of time separation.

Which traffic light tells us to go? ›

The traffic signal works on light signals and includes three colours: red, yellow and green. Here 'red' indicates that the vehicles must stop, 'yellow' means that the vehicles must slow down and finally 'green' means to go ahead.

What is the 4 color stop light? ›

NC State researchers are proposing a fourth color for traffic lights. Here's why. The "white light" would help self-driving vehicles control traffic flow and let humans behind the wheel understand what's happening. RALEIGH, N.C. — Green means go, red means stop, and yellow means slow down ahead of a stop.

What does a yellow light mean? ›

YELLOW—A yellow signal light warns you that the red signal is about to appear. When you see the yellow light, you should stop, if you can do so safely. If you can't stop, look out for vehicles that may enter the intersection when the light changes. FLASHING YELLOW— What does a flashing yellow light mean?

How many times does a traffic light change in a day? ›

Cycles may vary by time of day and by day of week (or not vary at all). The number of cycles and cycle length may not add up to exactly 24 hours. For example, if the cycle length is 75 seconds, there would be 115.2 cycles per day. An actuated signal may vary in cycle length.

Why do traffic lights change when no one is there? ›

Traffic engineers say the traffic light computer probably detected your vehicle. If you were the only person at that intersection, the computer changed the light to green quickly, to clear that intersection to get you through it.

Can you run a red light if it doesn't turn green? ›

Even if the stoplight is taking longer than usual to turn green, Tapley said you are not authorized to proceed into the intersection. “The only exemption for running a red light is when directed by a law enforcement officer or authorized traffic director,” Tapley wrote in an email to The Sacramento Bee.

What did traffic lights look like in the 1920s? ›

Detroit traffic officer William Potts created this three-color, four-way traffic signal in 1920. Previous illuminated signals used only red and green lights. The addition of an amber "caution" light made driving safer and the three-color signal became the standard by the mid-1930s.

How did traffic lights impact the 1920s? ›

The 1920s saw traffic lights pop up at major intersections across the United States and Europe. Bustling roads and bottlenecking traffic caused delays. They were also becoming increasingly dangerous for pointsmen. Birdhouse traffic light designs and manually operated electric ones were some of the early designs.

What did the first traffic lights look like? ›

A device installed in London in 1868 featured two semaphore arms that extended horizontally to signal “stop” and at a 45-degree angle to signal “caution.” In 1912, a Salt Lake City, Utah, police officer named Lester Wire mounted a handmade wooden box with colored red and green lights on a pole, with the wires attached ...

What did people use before traffic lights were invented? ›

Before electricity

The first traffic lights as we know them were used in London in the 19th century. They used a gas-lit flame to alert passersby of passing trains. This was meant to alert those riding horses of the presence of railroad activity.

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