City Mayors

The question of whether graffiti is art or vandalism is facing a vote in Bristol, U.K., the hometown of famed graffiti artist Banksy.

European cities are experimenting with trains that can switch from heavy rail (to reach suburbs on existing tracks) and street-running fixed link systems (to reach city centers).

The American Lung Association has released its annual list, and says that despite a new interest in green initiatives, the air in many cities has gotten dirtier in the past year.