Global Data Puts US Traffic Congestion in Perspective

Would you believe that of the 24 most congested urban areas in high-income countries, only four are in the United States? That is among the findings of a recent analysis by navigation services provider Tom Tom. The Amsterdam-based company is now producing its own travel time index, similar to the well-known TTI reported on annually for US metro areas by the Texas A&M Transportation Institute, which gives the ratio of travel time during peak periods and off-peak periods. (Thus, a travel time index of 1.33 means it takes 33% longer to make the same trip at rush hour.) Tom Tom’s report for the second quarter of 2013 provides such indices for each of the large urban areas in New Zealand, Australia, Canada, Western Europe, and the United States. The average of those indices is highest for New Zealand, followed by the averages for Australia, Canada, and Western Europe, with the United States bringing up the rear.

Next let’s look at individual urban areas, regardless of country. The 24 most-congested urban areas in wealthy countries are as follows:

Most Congested Areas in Developed/Wealthy Countries

I won’t make you read the list of the 22 least-congested rich-country urban areas, but only seven of them are outside the United States (Seville, Valencia, Malaga, Bern, etc.). The 15 least-congested metro areas in this country include Cincinnati, Birmingham, Rochester, Louisville, Phoenix, Kansas City, and Indianapolis.

At first glance, these results seem counter-intuitive—or at least contrary to what is taught in urban planning schools and believed by many transportation planners. The highly congested non-US urban areas generally have extensive mass transit systems and traditional central business districts—i.e., a monocentric urban form. The much less congested US urban areas are for the most part exemplars of what planners derisively call urban sprawl—i.e., multi-centric urban form, limited transit service, larger overall area, and significantly lower average densities. By the conventional wisdom, metro areas like Vancouver, Rome, Paris, Sydney, Hamburg, etc. should have lower traffic congestion than sprawling US urban areas like Phoenix, Indianapolis, and Kansas City.

Demographer Wendell Cox, who brought the TomTom findings to my attention, points out that there is, in fact, a strong association between higher densities and higher traffic congestion. But also, “Residents of the United States benefit because employment is more dispersed, which tends to result in less urban-core-related traffic congestion. Lower density and employment dispersion are instrumental in the more modest traffic congestion of the United States.”

Cox’s NewGeography report on these findings is online at: www.newgeography.com/content/004048-new-zealand-has-worst-traffic-international-data.

This article also appears in Robert Poole’s Surface Transportation Newsletter #122.