On March 17th, the French government enforced rules allowing only motorists driving cars with odd-numbered registration plates to enter the French capital and use the roads in the surrounding departments. This was the result of High pressure weather conditions, with hot days and cold nights, which allowed pollutants to build up in the city until pollution exceeded safe levels for 5 consecutive days.
News item about the smog:
An article from the BBC about free public transport
A feature from the BBC
An article from the BBC about the car ban
An explanation of the weather conditions leading to the smog from BBC weather
An article from the Economist about the car ban
Teaching Resources about Anticyclones: