Bicycles, pedestrian-friendly plazas and walkways, new bus lines, and parking meters are combining to transform parts of Mexico City from a traffic nightmare to a commuter's paradise. The Mexican capital, one of the world's most populated urban areas, has captured this year's Sustainable Transport Award, the Institute for Transportation and Development Policy (ITDP) announced Tuesday.

As recently as late 2011, Mexico City commuters reported enduring the most painful commute among respondents to an IBM survey. Based on factors such as roadway traffic, stress levels, and commute times, the city scored worse than 19 cities, including Beijing, China, and Nairobi, Kenya. Mexico City has seen its roadways swell beyond capacity to more than four million vehicles, which are owned, increasingly, by a growing middle class.  (See related photos: "Twelve Car-Free City Zones")