Lead in text:
As heard on All Things Considered, this NPR special series examines the future of cities across America.
More than half of the world now lives in urban areas. In the U.S., urban dwellers make up 83 percent of the population, and it's growing every day. What does it mean to live in a city today? What are the challenges for cities going forward? NPR explores urban life in the 21st century.
