Vehicular access to certain cities is now governed by the requirement to display a valid
Crit'Air Air Quality Certificate on your vehicle. If you need one in a hurry read my article, "
How to get a Crit Air Sticker Quickly".
It talks you through the process and there is a video to watch.
These areas have been designated 'low emission zones' and can be permanent (ZCR or 'Zone à Circulation Restreinte') or temporary (ZPA or 'Zone de la Protection de l’Air').
Basically, diesel vehicles made before 2006 are not allowed in these areas at all. Other vehicles should display the appropriate certificate (which you can apply for here and will cost you about €10).
If you are caught driving in a restricted area in contravention of the rules, you can be fined €68 for cars/motorbikes, and €135 for vans and lorries.
The main cities where this applies currently are:Paris, Gironde/Bordeaux, Hérault/Montpelier, Lille, Lyon, Marseille, Strasbourg, Toulouse and Poitiers
...but for a full list see our
Crit Air sticker page. The number of these Low Emission Zones are sure to be increased in the near-future, with climate change being such a high priority nowadays.
If you are driving past one of these cities - sticking to the main roads/ring roads and not actually driving through them - you shouldn't encounter a low emission zone and therefore don't need to display the sticker.