Common traffic light questions you should know!

You might have seen the traffic light hundreds of times. While you know it in its present form, do you know it results from 100 years of evolution?

Besides this, there are quite a few lesser-known facts about traffic lights worth highlighting. Today, we will answer a few questions that will help you uncover the truth behind the humble traffic light you see at almost every intersection.

Who invented the traffic light?

The traffic light was invented by a Nottingham railway engineer named J P Knight. It first came into use on December 10, 1868. The junction on which it was installed was outside the house of Parliament in London.

While it is true that the first motor cars came onto the road only in the 19th century but initially, the traffic light was installed for horse-drawn carriages.

The funny thing is, initially, policemen operated the red and green arms. During the daytime, the policeman operated the same, and gas-lit lanterns were used at night.

Unfortunately, safety was not exactly considered back then, resulting in a lamp exploding and killing a policeman in 1869. After that, the UK saw traffic lights only in 1925. 

How have traffic lights changed over time?

Initially, gas-fuelled traffic lights were used. At day time the lights were operated by the policeman. At night, gas-fuelled lanterns were used to indicate whether the horse carriages should pass by or stop. This was in the year 1868. However, due to an accident in 1869 because of gas-fuelled lights, the use of traffic lights was completely stopped in the UK.

In the US, in the early 1900s, towers were built to allow police officers to view the traffic. Depending on the traffic condition, police officers could use red or green lights to stop the traffic or let the traffic pass by.

In 1912 the American policeman by the name of Lester wire first envisioned the idea of an electric traffic light. Its first installation was done in Cleveland, Ohio, in 1914.

The present forms of traffic lights have three different colours: red, amber, and green. These were first installed in Detroit in 1920. However, still, these lights needed a person to control the lights.

Automatic traffic lights only came into being in the 1920s. Charles Adler Jr. further advanced these lights with the help of a sound detection system. Whenever the microphone detected honking, it changed to the lights accordingly. Once the light changed, it remained that way for at least 10 seconds.

Finally, computer-controlled traffic lights were invented in the 1950s. Toronto became the first city to use these advanced computer-controlled lights in the year 1967. These were able to detect vehicles in a much more accurate fashion. The switching between the lights was quite quick because of the same. Also, the traffic lights detected whether and changed the mechanism accordingly. In case of emergencies, they increased road safety.

Further advancement happened in the 1990s when timers were incorporated into the traffic lights. These drivers made it easy for pedestrians to cross the roads and let the drivers know how much time they had to wait before the light changed.

As you can see, over the years, many advancements have happened in traffic lights. The single inventor or country cannot be credited for the same. Collective evolution has happened due to the efforts of many.

Today, the traffic lights which we see are the most advanced of their type and are so common that they can be found at every intersection.

Do traffic lights have cameras?

Not all of them, but many traffic lights these days have cameras. These cameras aim to detect the drivers crossing the road even after the light has turned red. The camera might use the ground loop or sensors to detect the offence.

Whenever the traffic light for a particular section of the intersection becomes red, the system is activated. The camera takes photographs of any car that passes the intersection erroneously.

The camera, in most cases, can detect the vehicle details through the number plate of the vehicle. Later on, all these details are put into the computer to issue an online ticket to the vehicle owner.

If the system is not fully automated, merely the photos of the vehicle trespassing after the light has turned red are passed to the concerned authorities.

While most intersections or traffic lights don't have cameras, many of them do. Authorities are slowly ramping up the installation of such cameras to ensure that traffic control and ticket issuance are automated.

How do temporary traffic lights work?

Temporary traffic lights are also known as portable traffic signals. These are often operated in vehicle actuated mode. When the cars are detected on the road, they come into force and control the traffic. In most cases, their use is prohibited on the motorways.

Whenever authorities anticipate a spike in traffic on smaller roads, they often use these temporary traffic lights. These can also be used if there is partial road closure and better traffic management is required.

Temporary traffic lights can also be operated in a fixed time or manual mode. However, usually, vehicle actuated mode is in use. This is the mode in which there is the least delay between light changes.

Who has priority when traffic lights are out of order?

No civilian vehicle owner has the priority when traffic lights are out of order. Every vehicle driver has to see and avoid driving mechanisms while crossing the intersection.

Even the most advanced traffic lights might develop a snag sooner than later. It might be weather-related or due to the wear and tear of the parts. That is why such situations do arise.

Even when the traffic lights are out of order, emergency vehicles are higher in the hierarchy when it comes to the right to passage.

Can you ever pass a traffic light if it's red in any situation?

No, you cannot pass the traffic light if it's red. While many people do so when they move out of the way for an emergency services vehicle, you can still be fined for the same.

That is why, when there is an emergency services vehicle behind you, make sure that you move somewhere else to provide it with a clear way rather than jumping a red light.

Conclusion

Next time around, you take a look at the traffic light, you will remember that it is a result of 100 years of evolution. Besides that, you will know the correct way to drive around the intersection with traffic lights. In case there is some confusion, wait for the green light; otherwise, a camera might be around to issue you an online ticket.