text: Another insight to reduced car zones brings Paris' incident with smog. Paris' officials created a system that would in fact lower smog rates. On Monday, the motorists with even-numbered license plates numbers would be ordered to leave their cars at home, or they would suffer a fine. Same rule would occur on Tuesday, except motorists with odd-numbered license plates were targeted with fines. Congestion, or traffic, was reduced by 60% after five days of intense smog. Diesel fuel played a huge part in this pollution, having the fact that 67% of vehicles in France are of Diesel fuel. The impact of the clearing of smog, resided in banning the Tuesday rule of odd license plates.