After opening several new lines this year, it's got 282 stations and 420 km (261 mi) of lines, compared to 408 km in London and 368 km in New York.
Mayor Michael Bloomberg has an ambitious plan to keep raw sewage out of the city's waterways.
The creation of a modern rail network in the United States is becoming just another political football.
Jeanne Park of PBS's Need to Know speaks with Mau about his love of the suburbs, cup holders, and the challenge of rebranding climate change.
Whether you do it with a Mosquito or with old-fashioned security guards, the routine dispersal of teenagers does raise issues about the nature of public space -- the vital essence of a dynamic and productive city.
Hopes were high for a "who's greener?" argument between Seattle Mayor McGinn and Portland Mayor Adams at a recent talk. Alas, the mayors played nice.
Does the sight of swarms of cyclists in your city leave you feeling all warm and fuzzy too?
Middle school kids from Brooklyn turn a spotlight on their neighborhood's vacant lots.
Mad Men's Vincent Kartheiser is a successful actor in Los Angeles who doesn't own a car. He doesn't drive because he wants to interact with others.