An easy way to Reduce emissions

After today's class discussion on car emissions and what can be done about it I am still split on whether required emission testing or random radar inspection is the best method. One idea that I did find here towards the bottom of the page is benefits of turning off your engine when stopped, except for in traffic. Instead of leaving your car on to keep it warm turning it off reduces emissions greatly. Other emission reducing tips that are much more convenient than not driving at all can also be found at the above mentioned link.