n a fascinating and wide-ranging debate, four Principal Voices shared their views on this most complex and important of subjects: Adriana Lobo of Mexico City's Center for Sustainable Transport; Claudia Sheinbaum, Minister of Environment for Mexico City; E

EMBARQ, the World Resources Institute's Center for Transport and the Environment, the U.S. Environmental Protection Agency, the Mexico City government, the Mexican Ministry for Environment and Natural Resources (SEMARNAT), and the Center for Sustainable T

Lee Schipper describes an innovative model of rapid transit developed in a collaboration between the municipal government, international lenders, and NGOs is liberating commuters in Mexico City and keeping 35,000 tons of carbon out of the atmosphere every

Hong Kong's pollution problem seem utterly hopeless. But other cities have been where it is now – and cleaned up. Five cities who beat their own smog problems give some advice to Hong Kong.

America’s landscape of scattered suburbs and devoted commuters make it difficult to encourage mass transit on a nationwide scale. It typically takes 25 to 50 years to create a successful public transportation system, but few cities have started down tha