One less car

I am 28 and I never learned how to drive a car. I have lived in cities most of my life and have always loved being able to get from point A to point B using my own self propelled power. This weekend I have been doing research on organizations that promote using alternative transportation and found Bike Maryland. They are an organization that promotes biking around the state. I am interested in creating a "one less car" campaign for Bike Maryland.
I am still trying to figure out how I am going to show cause and effect with this campaign but I have some ideas.