text: According to source 2, Robert Duffer, claims in paragraph 1, Paris enforced a partial driving ban to clear the air of the global city. They put a 22-euro or $31 fine on anyone that did not leave their cars at home, according to paragraph 2. During that fine, 4,000 drivers were fined. Reducing car use can make the air or sky clear without smog, Diesel fuel was to blame. Paris has typically more smog than other European capitals, because Diesel makes up 67 percent of vehicles in france.