As urban areas continue to expand, traffic congestion is becoming an increasingly pressing issue that needs to be addressed. The combination of population and economic growth in cities worldwide is putting significant strain on transportation networks. Outdated infrastructure and inefficient road planning fail to keep pace with demand. Additionally, the surge in e-commerce has led to a rise in freight traffic, further complicating the situation.
These trends are highlighted in the TomTom Traffic Index, an annual report that provides a unique overview of global traffic trends. The 14th edition of the annual report features 500 cities across 62 countries on 6 continents.
The TomTom Traffic Index uses unified metrics to rank these cities based on their average travel time as well as congestion levels. It gives city-by-city information that can help urban planners and policymakers tackle traffic-related challenges and make informed decisions.
Ralf-Peter Schäfer, Vice President of Traffic, TomTom, said: “Urban mobility is the result of the interplay between static factors that determine the potential for efficient travel, and dynamic factors that create variations and disruptions experienced by road users. Our traffic data allows urban planners to understand these factors, for them to design cities that balance mobility, safety, and accessibility. Without a shift towards more regulation and sustainable transportation options, we risk worsening congestion that impacts everyone in our cities.”
In 2024, 379 cities out of 500 (76%) saw their overall average speed decrease compared to 2023. Despite this decrease, average speeds under optimal conditions, characterized by free-flowing traffic, remained stable and even showed slight improvements in most cities. This suggests that the observed deterioration in average speeds is primarily driven by dynamic factors affecting congestion levels rather than changes in road infrastructure.
The differences in travel times (or average speeds) across cities stem from a combination of static and dynamic factors that significantly influence traffic flow and overall driving conditions.
Static factors are fixed aspects of a city’s infrastructure and planning that influence travel times. The design of road networks, including highways, arterial roads, and residential streets, impacts traffic flow. Narrow streets, one-way systems, and complex intersections can slow movement, while wider, multi-lane roads support smoother flow. Speed limits, often set for safety, and high-density areas with frequent stops or pedestrian zones also affect driving speeds. Traffic light synchronization, roundabouts, and stop signs further shape navigation efficiency.
Complementing these static factors are dynamic factors, which are ever-evolving conditions that impact traffic flow on a daily basis. Traffic congestion during peak hours or seasonal traffic surges leads to higher vehicle density, causing delays. Unexpected obstructions, such as car accidents, construction projects and road closures can create bottlenecks, disrupt normal traffic patterns, and lead to rerouted traffic. Additionally, rain, snow, or fog can reduce visibility and traction, forcing drivers to adapt their driving styles. The highest levels of congestion are often reached on days when weather conditions are particularly bad.
In 2024, Barranquilla in Colombia was the city with the lowest average speed. The average speed over the year is 10.3 mph, which means that it takes almost 35 minutes on average to complete a simple 6-mile journey. Three Indian cities feature in the top 5 list of slowest cities. London, the first European city in the ranking, is in 5th position, with an average speed of 11.2 mph in the city. Yet the English capital is only 150th in the congestion ranking, which measures only the dynamic factors of slow speed.
The level of congestion only takes into account the dynamic factors that lower the average speed in a city. With a congestion rate of 52%, Mexico City is the city in which traffic has the greatest impact on the deterioration of journey times compared with ideal traffic conditions. This means that on all routes surveyed throughout the year on the entire road network, journey times are 52% longer than those recorded in Mexico City when traffic was free-flowing.
Because of rush-hour traffic in Lima, Peru, and Dublin, Ireland, motorists in these two cities lost an average of 150 hours in traffic jams (on a typical 10-kilometer journey, made every working day in the morning and evening) – almost a week’s worth over the year.
The TomTom Traffic Index utilizes floating car data collected from various sources to enhance our traffic services. For the latest edition of the report, TomTom analyzed a representative sample covering 458 billion miles driven in 2024, allowing to track and demonstrate how traffic patterns have changed in cities worldwide.