Officials in Paris said the one-day ban on driving cars with license plates ending in even numbers led to a significant drop in pollution. The French Environment Ministry said Monday's scheme, which allowed only drivers with plates ending in odd numbers to use the roads in Paris and surrounding areas, was effective in bringing the pollution around the French capital back down to safe levels after five days of high smog levels, the BBC reported Tuesday. About 700 police officers manned about 180 checkpoints on Paris roads to hand out fines for violators. Taxis, electric vehicles, hybrid vehicles and cars carrying three or more passengers were exempt from the ban. Police said nearly 4,000 tickets had been issued by midday Monday. Officials said Monday's scheme, a repeat of a measure imposed once before in 1997, was effective and all cars would be allowed on the roads Tuesday.