Why do traffic jams occur?

22 Nov, 2019 • 6 min read
Why do traffic jams occur?

Everyone hates traffic jams. They are time-consuming and frustrating, especially when you are rushing for time.

The most common reasons for traffic jams are well documented. However, in this article, we dig deeper into the science of traffic jams and explain why and how they happen.

1) Peak period traffic

Traffic is usually heaviest during the peak hours of 7-9 am in the morning and 5-7 pm in the evening. ERP (Electronic Road Pricing) gantries are meant to alleviate traffic jams during peak hours.

However, having many cars on the road is only a partial explanation to why there congestions form.

2) Selfishness: The real reason for no-reason traffic jams

In a study conducted by Japanese researchers, evidence suggests traffic jams are really formed by selfishness.


Drivers tend to drive as fast as possible when they see space in front of them. However, there will be occasions where drivers misestimate their speed and end up braking as a result.

The braking tends to cause the car directly behind to do the same, resulting in the same situation but even more braking. The process repeats until a congestion is formed.

This is one of the main reasons why traffic jams can randomly form even without any road disturbances.

More cars + selfishness = Traffic Jams

The problem is even worse when there are a large number of cars on the road as misestimations tend to happen way more often and the problem compounds even more.

While it is hard to control the behaviour of others (at least until self-driving cars take off), you can play your part by changing your own behaviour but trying to maintain a more constant speed without speeding too much.

Here are some ways that can help you drive efficiently while also saving fuel costs.

3) Road disturbances / blockages

Road disturbances / blockages could come in the form of car breakdowns, accidents, road works, plant pruning or even illegally parked vehicles.

Only a certain number of cars can travel simultaneously side by side in any given road. Road disturbances essentially shrink this number by blocking out lanes while cars in block lanes have to change lanes, which can also potentially cause congestion.

Using an app like Waze, which helps to identify road blockages, can help you avoid traffic.

4) Navigation apps could be causing traffic jams

Navigations apps such as Google Maps and Waze have become popular in the past years. Most private hire vehicle drivers use it.

These apps were built for a single objective – getting users from point A to point B in the shortest time possible. Unfortunately, the fastest routes could be the same route for many people, resulting in unintended congestion.

One way to reduce traffic in “fastest” routes is potentially spreading drivers across different routes. However, this also has its own issues (eg. Who gets the best routes, etc.).

Thankfully, these apps are getting smarter and most can identify traffic jams, allowing motorists to avoid them.

Traffic jams are bad but breakdowns are worse

Car breakdowns are even more frustrating than traffic jams. Regularly servicing your car can prevent your car from braking down.

Simply chat with us to get quotes or recommendations or discover suitable workshops here.

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