Paris traffic. We’re in the middle of la rentrée des vacances – returning from vacation. “La rentrée” is synonymous with “early September,” two words heavy with all the activity related to back-to-school and return-to-work. After a month of comfortably uncrowded metro cars and bike-friendly traffic, the city is filling up with Parisians, rested and ready for action. But by October they’ll be planning their next break.