text: One solid reason why not using cars as much is the pollution going in the air.  In Paris, France motorists with even numbered license plates were ordered to leave their cars at their house or else they would be fined.  The next day odd numbered license plates motorists had to leave  their vehicles at home.  It was a hardship at first to get people to follow these new rules, but after about five days everything started to cool down.  The pollution had dropped 60 percent in Paris which is exactly what the city was looking for.  Limiting the car usage didn't just save pollution from going in the air, but also there wasn't as much traffic as there usually was.  It also made Paris a safer place to be outside and not damage the citizens lungs.  The capital city of France also made transportation free Monday-Friday to help the cause.  Soon enough people that had both license plates could drive on the same day.