text: Another way people are cleaning the air and limiting car usage is a car free day. In Bogota, Columbia  the gial of this is to promote alternative transportattion and reduce smog. Bogota is a large city homed to 7 million citzens. This idea of a day without cars was started in Bogots in the 1990's, because of this parks and sports centers have booms and many miles of bike trails have been constructed for the recreational; use but also to urge people to not use cars and clean the air.