Traditionally, speed limits were communicated through analog means like road signs.
If you’ve used a car navigation app or driven a new car lately, you will have noticed that the speed limit will now show up in the app or directly in the car dashboard. This is thanks to Intelligent Speed Assistance (ISA), a new technology designed to deter speeding and improve road safety. Since speeding ranks among the main contributors to the 1.19 million fatalities that occur on the world’s roads every year, the emergence of a new tool to effectively deter speeding is a promising development for vulnerable road users everywhere.
However, the effectiveness of ISA depends on accurate and comprehensive speed limit data—something many cities and national road authorities, especially in the global south, are currently lacking. The World Bank’s Global Road Safety Facility (GRSF) has been looking at solutions to close this gap and allow more communities to leverage the benefits of ISA. With financial support from Bloomberg Philanthropies, our team is now helping cities across Latin America digitize their road traffic regulations and create open spatial databases of speed limits.
The growing popularity of Intelligent Speed Assistance
The shift is already happening, with a growing number of governments and institutions looking to ISA as a way to improve road safety. In the European Union (EU), all new cars must now include ISA. Transport for London has retrofitted its bus fleet with ISA technology following successful trials in 2021, and similar efforts are underway for its commercial fleet. In the US, the National Transportation Safety Board (NTSB) recently recommended ISA for all new cars, while Washington, D.C. just passed the first ISA regulation in the US, mandating it for repeat speeding offenders. New York City also conducted an ISA pilot for city-owned vehicles with positive results.
Even for those who cannot afford a new vehicle, speed management has been evolving rapidly. We are now seeing almost all navigation apps, including Google Maps, Apple Maps, and Waze alerting drivers when they go over the speed limits, therefore acting as a de-facto GPS-based ISA instrument.
This is a significant development, especially when you consider the ever-increasing popularity of navigation platforms around the world. Google’s latest EU Digital Services Act report showed that, in the EU alone, Google Maps had 287 million monthly users (~64% of the population) in early 2024, while Waze had 45.5 million users (~10%). In Latin America, Waze reported 16 million users in Brazil and 2 million in Mexico, with 32% of drivers in Mexico City using it. Companies like HERE Technologies and TomTom also power ISA systems in millions of vehicles globally. And let’s remember these platforms, such as Waze’s Transport SDK program, also serve as the navigation engine for commercial fleets of all kinds—including logistics, delivery and ride-hailing services—making the potential reach even greater.
A persistent data gap
Although the rise of new speed management technologies is welcome news, there is one major caveat: speed limit data coverage remains extremely uneven, particularly in the global south. Google Maps API covers speed limit data in 47 countries, but only eight are in the global south; Apple Maps covers 40 countries, but just one in the global south.
Even when data is available, speed limits may often differ widely across navigation platforms, or might be different from what is indicated on physical traffic signs.
What exactly is the extent of the challenge in Latin America, and how can we address it? To find out, we analyzed speed limit data from navigation platforms like HERE, TomTom, and OpenStreetMap (OSM) for cities such as Bogotá, Buenos Aires, Rio de Janeiro, and Mexico City. The findings, presented to city officials, revealed significant discrepancies—speed limits on identical streets sometimes varying from 20 km/h to 80 km/h depending on the platform. A further city-scale analysis also confirmed these inconsistencies, as shown in the graph below.
Lastly, we reviewed the official speed limit data that is currently available. This included checking if there was a complete and navigable road network and an inventory of speed limit traffic signs, among other information.
Using OSM and this awesome Overpass query (feel free to tweak to add any city), we also assessed total drivable road lengths with and without speed limits across several cities in Latin America and Europe. If curious, here is another query that will find streets that have high or NULL speeds within a 30 mts radius of schools or hospitals.
These discrepancies underscore the importance of official speed limit databases to ensure consistent and accurate information across platforms. Without such data, information asymmetries can compromise road safety efforts.
In our next blog post, we will showcase the outcome of our work with these cities. This will include some more detail on our engagement with the city of Rio de Janeiro, which recently collected street-level imagery over 3,300 kilometers of roads using Mapillary’s object detection algorithms and off-the shelf equipment to inventory 53,389 traffic signs—a major step toward building comprehensive spatial speed limit databases. Stay tuned!
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