30. Mexico CityContenderPrivate cars: 22%Public transport options: Metro, bus, light rail, commuter railMonthly public transport pass: $25The city's transportation plan addresses current challenges, such as congestion and infrastructure, and promotes the use of active modes of transportation and electric vehicles for sustainable mobility. The city has the fifth-largest public bike-share system in the world.Photo: Santiago Castillo Chomel / Shutterstock