The system was introduced by the French government as a way to reduce harmful vehicle emissions in areas where air quality is poorest, such as larger towns and cities.

In these areas, certain vehicles can be refused entry based on the Crit’Air sticker displayed on the windscreen – either all the time or on certain days where air pollution levels are dangerously high.

There are currently two different types of government-defined low emissions zones in France:

• Permanent low-emission zones (known as ZCR – Zone à Circulation Restreinte)
• Temporary emergency low-emissions zones (known as ZPA – Zone de la Protection de l’Air)

In addition, certain French towns and cities now have emergency schemes that can restrict certain vehicles in the event of particularly high pollution.

If driving in any of these zones, a Crit’Air sticker should be affixed to the right-hand side of the car’s windscreen and should be clearly visible at all times.

All eligible vehicles need to display a Crit’Air vignette on their windscreen to be able to drive and park in restricted traffic zones, such as permanent low-emissions zones and emergency low-emissions zones.

Not all vehicles are eligible for the vignettes. Cars registered before January 1997 and motorbikes and scooters registered before June 2000 are ineligible, and cannot be driven at all where restrictions apply.