text: The smog levels in Paris are absolutely outrageous, "[Last] week Paris had 147 micrograms of particulate matter (PM) per cubic meter compared with 114 in Brussls and 79.7 in London, Reuters found" (Duffer). The smog amounts , according to Duffer, were almost at the level of Beijing, China which is the most polluted place on earth. By enforcing a short driving ban, set for only a day, on even-numbered license plates to clear the heightening amount of gases in the air, the smog levels dropped enough to release the ban set for odd-numbered license plates the next day. This experience proves that limiting car usage can prevent air pollution exponentially.