I live in Paris, cars haven't all been banned. Some streets have been made pedestrians only and some lanes have been converted into bike lanes, but overall you

I live in Paris, cars haven't all been banned. Some streets have been made pedestrians only and some lanes have been converted into bike lanes, but overall you can drive almost everywhere in the city (although that was always painful). We have that certificate you mention. Today in most large cities in France, some streets are forbidden to cars that have a bad "Crit'air" score. It's a sticker you have to order online, with a number from 1 to 6. What number you receive is dependent on your car's model and its age. You have to put it under your windshield or risk getting fined by the police.