Mobile apps, sensors, and other technologies help cities handle growing challenges.
Twenty years after it first surfaced, data-driven police work is getting more pervasive but remains controversial.
China has put political muscle and technology into Tianjin Eco-City.
Technology can make cities increasingly machine-like or more social and creative, says author Anthony Townsend. Both models can work.
U.S. carmakers are leading the development of vehicle communications technology, and it could be a boon to city planners.