As the Chart of the Week shows, the world’s fastest roads are found in richer economies including the United States, Portugal, Saudi Arabia and Canada. The slowest roads are found in the poorest countries—another obstacle to inclusive growth. An interactive version of the map can be viewed :

Simplicity is a main feature of our score. Average speeds are easy to calculate and simple to monitor frequently. This makes them an inexpensive complement to other connectivity metrics that rely on satellites or surveys. Our research shows that road quality is highly correlated with travel times.

It is difficult to distill road quality into a single statistic. For example, speed does not capture road safety, the availability of alternate forms of transport such as rail, or congestion during peak hours or seasons (when farmers might all take to the roads at once to get their produce to markets). Furthermore, they might not fully capture the engineering challenges of building quality roads in diverse and difficult terrain.

Nonetheless, this simple metric can support policymakers and planners in assessing their road infrastructure relative to peer countries and the value of future road investments. It can also be easily extended to monitor speeds in smaller roads that can be critical for many in rural areas. This can help countries design policies to overcome road bottlenecks and improve their competitiveness by moving people and goods more expeditiously.