Here’s TomTom’s list of the ten most traffic-clogged cities on the planet, ranked by their respective congestion levels, which notes the percent increase in overall traffic times during peak periods versus those rare times when traffic is flowing freely
TomTom’s traffic index is based upon comparisons of travel times during non-congested hours against those in peak hours experienced by passenger vehicles. All data is based on actual GPS-based measurements. The index takes into account both major highways and local roads. To download the full index results for over 180 world cities, log onto www.tomtom.com/trafficindex.