【Q3】Almost half the centre of Paris will be accessible only by foot or bicycle this Sunday to mark World Car-Free Day. 【Q4】This is in response to rising air pollution that made Paris the most polluted city in the world for a brief time. Mayor Anne Hidalgo promoted the first World Car Free Day last year. Hidalgo also has supported a Paris Breathes Day. On the first Sunday of every month, Paris clears traffic from eight lanes of the main road. About 400 miles of streets will be closed to cars. It is expected to bring significant reduction in pollution levels. “Last year’s car-free day showed a 40% drop in pollution levels in some parts of the city, according to an independent air pollution monitor”, reports the Guardian, “and some levels dropped by 50% in the city centre.”