Prior to taking a political leap of faith and adopting bus rapid transit, Mexico City had, in the words of one transportation director, “lost control of its transit system.” Before, a chaotic fleet of green-and-gray microbuses competed to pick up passengers wherever they stood. Now, Mexico City represents the best of what BRT has to offer. Jumping numerous political hurdles — like Bogotá before it and later Johannesburg, Tehran and Guangzhou, China — the megapolis took a major political risk when it pushed for BRT. It’s a risk U.S. cities have been reluctant to take until recently; in several cases, city planners have opted, to poor reception, to build watered-down versions of BRT, prompting questions about whether the U.S. is falling behind the rest of the world. Mexico City-based journalist Lauren Villagran takes a look at not only why American cities have lagged in this department, but also at how the cities that set the BRT standard plan on dealing with future growing pains as their systems expand.