Need to pause at the curb to wait for a passenger or idle at a stoplight for more than 10 seconds? Try turning your motor off and then starting again when you need to move. Idling your motor for more than 10 seconds at a time is a pure waste of gas and an unnecessary source of pollution. Turning your engine off when it isn't needed is one of the simplest ways that you can solve the problem of transportation pollution. Make it a habit to switch off the ignition when you aren't going anywhere and you'll have made a small but significant start at making the Earth's atmosphere cleaner.