Ile-de-France Mobilités (IDFM) and Airparif unveiled on Monday a map of air pollution in 44 Paris metro and RER stations. Three of them show "high levels" of fine particle concentration.

A single fare on the Paris Metro, bus, central regional rail (RER) system, and certain tram lines, typically costs 2.15 EUR (about $2.35), and books of 10 single ride tickets can be purchased for ...

According to Google, “Google Maps is showing helpful transit routes provided by Île-de-France Mobilités to navigate Paris during the Games.” Other apps split the difference.