Cities in developing Asia are growing at breakneck speed, and transport infrastructure is struggling to keep up with demand.

One of the main challenges arising from rapid urban growth in the region is severe traffic congestion, which has become a major concern for urban transport practitioners as well as city residents.

But before we take action on traffic, we should look into what causes congestion, and how costly it is to cities. Surprisingly, little scientific research has been conducted on these topics by urban or transport scholars, and even less by economists.

Among other factors, a key challenge is lack of good data to systematically measure people’s day-to-day travel.

In a recent Asian Development Policies Lecture hosted by ADB, Prof. Gilles Duranton from the University of Pennsylvania’s Wharton School shared a series of recent innovative studies on urban transportation that use information on real-time simulated trips gathered from Google Maps.