Partially Banning Cars for a Day in Paris Actually Worked

Back in March, air quality in Paris got so awful that the city took some drastic measures. With weather patterns keeping noxious particulate pollution close to the ground, the city made all public transportation free of charge. The next day, they went one step further, banning all cars with odd-numbered number plates from driving within the city proper. This unprecedented move is now back in the news for a compelling reason: Apparently, it worked.

According to Paris air quality monitor Airparif, keeping odd-numbered cars out of central Paris for a single day made a substantial difference. Within Paris proper, road traffic dropped by 18 percent that day, with drops of 13 percent in the Petite Couronne area that surrounds inner Paris. In the suburbs further beyond, traffic dropped by 10 percent. When compared to the seven days before, all this reduced levels of pollution by PM-10 within the city by 6 percent, with levels 10 percent lower than normal at rush hour on the Beltway. Nitrogen dioxide levels, meanwhile, dropped by 10 percent overall, and by 30 percent on the Beltway at rush hour.