The cost of traffic jams on the driver's wallet is also quite significant. In Paris, driving a petrol-powered car during rush hour increases the cost of driving by 40%, compared to driving during optimal times (when traffic is at its lowest). By teleworking one day a week, a Parisian driver would save US$170*.

The traffic index also allows us to determine the impact in CO₂ emissions when we drive during rush hour. For example, a Londoner who uses their petrol car every day to go to work emits 1.1t (2412 lbs) of CO₂ per year*. By working from home one day a week, that would be 219 kg (482 lbs) fewer emissions.

Ranking: Cities with the highest CO2 emissions per driven mile at rush hour

Average annual CO₂ emissions based on a 6-mile round trip (=12 miles total) driven daily at rush hour, in kg of CO₂.

2023 TomTom Traffic Index: New year, new methodology

For this edition of its Traffic Index, TomTom has modified its approach to calculating the costs of driving. This year, we’re assessing the time per mile driven, and simulating how long it takes to complete a 6-mile journey within a city. For the first time, we also worked on 2 analysis zones: the metropolitan area of each city (varying according to the size of the agglomeration), and the city center which corresponds for all cities to the complete road network within a radius of 5 kilometers (ab. 3 miles) around the center.

This methodology gives TomTom a deeper insight into traffic that more closely represents real-world driving conditions. It also allows for a more accurate comparison of driving conditions between cities, as the new method also identifies cities where the infrastructure (ratio of express lanes, traffic lights, speed limits, etc.) supports a faster or slower base speed. This new method quantifies the time and money drivers lose to road traffic, serving as a foundation for them to reconsider their travel behavior and make informed choices that benefit them as well as the environment.

Find out more about the TomTom Traffic Index and discover how your home city fared in 2022 at www.tomtom.com/Traffic-Index.

* on average, for a 6-mile journey driven twice a day (morning and evening) at rush hour

Notes to Editors

About the TomTom Traffic Index
Urban mobility is a key contributor to issues such as climate change, health and economic development and the TomTom Traffic Index has become the barometer of mobility patterns around the world. TomTom’s traffic data, which is powered by 600 million connected devices, is an authoritative indicator of how people move, economic activity levels, global trade and much more. For years, TomTom’s Traffic Index has been used by analysts, corporations and the media to explain a world in flux.

Which data does TomTom use for the Traffic Index?
We source our traffic flow data from over 600 million devices, such as in-dash car navigation (7 out of 10 connected in-dash navigation systems in passenger cars currently sold in Europe are powered with TomTom Traffic), smartphones, personal navigation devices and telematics systems. Each day, TomTom collects from these sources over 61 billion anonymous GPS data points around the world, covering a total distance of 3.5 billion kilometers driven. This real-time data is archived and accessible as historical data right away. Based on this historical data, TomTom can assess speed profiles and traffic patterns for each time of the day and each day of the week. 58 billion driving hours have been accumulated in TomTom’s historical traffic data over the past decade.