Building Better Cities

Computer scientist Daniele Quercia describes how "happy maps" can give you not the most efficient, but the most beautiful route.

Political theorist Benjamin Barber argues that cities and city mayors are the key to bypassing political gridlock and solving many of our global challenges.

Atlanta Mayor Kasim Reed says mayors are in a position to accomplish a great deal, because they're locals. They can see a city the way "people who are most in need of help see it," he says.

Fast-growing cities are often riddled with violence, drug trafficking and unemployment. Security researcher Robert Muggah explains how some cities are using new approaches to address these problems.

For Amanda Burden, a city is defined by its public spaces. The former city commissioner of New York City explains why a promenade, a park or even a park bench, are vital to a city's ability to thrive.