# Istanbul may have the worst traffic congestion in the world

By [Brandon Donnelly](https://brandondonnelly.com) · 2023-02-01

congestion-level, istanbul, mobility, tomtom-traffic-index, traffic-congestion, urbanism

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I just learned about the [TomTom Traffic Index](https://www.tomtom.com/traffic-index/ranking/) today. It covers 404 cities across 58 countries, and uses anonymized traffic data from more than 600 million drivers (people who use TomTom's tech) to come up with a list of the cities with the worst traffic congestion.

Here's the global top 10 (for 2021):

![](https://storage.googleapis.com/papyrus_images/759c31d677dc88e69482e34a69eb42ae.png)

  
And here's the North American top 10 (also for 2021):

![](https://storage.googleapis.com/papyrus_images/8b03c732e71079c94ca3eeecc105f909.png)

The way to interpret these congestion level percentages is to think of them as additional time over and above baseline free-flowing traffic times. For example, a 62% congestion level for Istanbul, means that a trip that would take 30 minutes without any traffic congestion, will instead take, on average, 18.6 minutes longer (0.62 x 30 minutes).

We all like to complain about traffic in our home city, but these percentages certainly help to put things into a global perspective.

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*Originally published on [Brandon Donnelly](https://brandondonnelly.com/istanbul-may-have-the-worst-traffic-congestion-in-the-world)*