About

The TomTom Traffic Index provides drivers, city planners, auto manufacturers and policy makers with statistics and information about congestion levels in 403 cities across 56 countries on 6 continents.

Now in its 8th year, the Index gives even more historical insight into congestion in urban centers and offers ideas about how traffic can be alleviated.

The Traffic Index is a key initiative in our ongoing mission to create a safer, cleaner, congestion-free world together with our partners and drivers.

Our Methodology

We’re often asked how we come up with the rankings presented in the TomTom Traffic Index. Unlike our data, our explanation is simple.

The congestion level percentages represent the measured amount of extra travel time experienced by drivers across the entire year. We start by establishing a baseline of travel times during uncongested, free flow conditions across each road segment in each city. We then analyze travel times across the entire year (24/7) for each city – and compare this information against free flow periods to derive extra travel time.

An overall congestion level of 36% means that the extra travel time is 36% more than an average trip would take during uncongested conditions. Average times are of actual taken trips, across every vehicle in the entire network, 24/7. Travel times in free-flow (uncongested) conditions are not based on speed limits but on actual trips made.

We also perform the same calculations for individual hours of each day of the week, so it’s possible to see how high congestion levels are in each city during the busiest times of the day, including morning and evening peak hours.

The TomTom Traffic index statistics are calculated from anonymized GPS data collected via navigation devices, in-dash systems and smartphones.

What's New - Big Data

The TomTom Traffic Index is based on the same statistics and methodology as our previous reports, but with significantly more data and expanded coverage, it is even more robust and reliable.

This year we have added cities in India, Japan, Egypt, Colombia, Peru, Ukraine, Israel and Iceland for the first time.

The most pronounced difference is that this year’s Index includes figures for both 2017 and 2018, so it’s possible to see year-to-year changes. The Traffic Index website has also been revamped so it is easier than ever to explore city statistics – including LIVE traffic information – and insights.

13
new cities
expanded
coverage
year-to-year
comparison

Definitions

CONGESTION LEVEL (EXTRA TRAVEL TIME)

Increase in overall travel times when compared to a free flow situation. For example, a congestion level of 36% corresponds to 36% extra travel time for any trip, anywhere in the city, at any time compared to what it would be in local free flow conditions.

The TomTom Traffic Index figures are based on speed measurements from TomTom's historical traffic database. These speed measurements are used to calculate travel times on individual road segments and entire networks. By weighting the number of measurements, busier and more important roads in the network have more influence on the city’s congestion level than quieter, less important roads. This ensures the statistics match the user experience of driving in cities.

We use four different colors to indicate the severity of the congestion level (extra travel time) in a city:

> 50%
25% - 50%
15% - 25%
< 15%
DATA COVERAGE
The kilometers or miles of GPS data from actual driven trips used to calculate the Traffic Index statistics in each city. This is reported separately for highways and non-highways.
HIGHWAYS/NON-HIGHWAYS
Statistic which only takes measurements on highways/non-highways into account, based on the industry standard that defines functional road class.
EXTRA TRAVEL TIME PER DAY
Extra travel time during peak hours compared to a one-hour period during free flow conditions.
EXTRA TRAVEL TIME PER YEAR
Extra travel time during peak hours as compared to a one-hour period during free flow conditions, multiplied by 230 working days per year.
MORNING/EVENING PEAK
The busiest one-hour period in the morning/evening as defined per city based on actual traffic measurements.
MORNING/EVENING PEAK CONGESTION LEVEL
Increase in morning/evening peak travel times when compared to free flow conditions.
FREE FLOW
A traffic situation in which travel times are not impacted by congestion. Typically occurs at night but can happen any time of day.
CONGESTION LEVEL BY TIME OF DAY
This table shows the congestion level for each hour of each day of the week, on average across the entire year, for each city.
TOTAL ROAD NETWORK LENGTH
Total length of evaluated road system.
WORLD RANK

The rank and the background color of the world rank icon is determined by the congestion level (see color legend).

5
This icon shows a world ranking of 5
FILTER RANK
Rank of cities based on congestion level in the selected list as defined by the user.
CITY DEFINITION
The TomTom Traffic Index uses the same methodology and data for all cities included across the globe. TomTom has created our own definitions of the metropolitan areas of the cities in the report, because municipal and statistical boundaries are not uniform internationally in their size and coverage of the actual urban area.

Definitions: Live TomTom Traffic Statistics

CONGESTION LEVEL NOW

This is the current, ‘live’ value showing the amount of extra travel time average drivers are experiencing in the city due to traffic congestion. It is calculated using TomTom’s real-time traffic information as opposed to the historical data used for the Traffic Index. In the associated graph it is possible to look back at the recent history of this number.

TRAFFIC JAMS NOW

This is the current number of traffic jams (and their total length) right now, based on TomTom’s real-time traffic information.