Department of
Environmental Quality

An idling engine gets the worst possible gas mileage –
zero miles per gallon.

DEQ's Anti-Idling Program

The Clean Air Zone Program is designed to encourage Idahoans to turn off their engines instead of idling. The program began in 2004 with a campaign aimed at encouraging school bus drivers and others not to idle on school grounds. To date, more than 300 Idaho schools and child care facilities have voluntarily joined the program.

In 2006, the program expanded to discourage vehicle idling at community facilities where idling is common, such as airports, libraries, parks, sports areas, and universities. To date, more than 30 Idaho communities have joined the program.

Subsequent efforts have focused on encouraging businesses to join the Clean Air Zone program. Businesses with delivery vans or truck fleets are great candidates for participation in the program, as are businesses with loading docks or drive-through lanes or parking lots where vendors or customers often sit and idle.

Why is Vehicle Idling a Problem?

It wastes fuel.

Idling for 10 seconds or more uses more fuel than restarting your engine. Idling for 10 minutes a day wastes an average of 26 gallons of gas per vehicle per year. People sometimes think vehicles should idle for several minutes before being driven. This is not true. Modern engines do not need more than a few seconds of idling time, even in cold weather, before they can be safely driven. In fact, the best way to warm up a car is to drive it, since that warms up the catalytic converter and other mechanical parts of the car, in addition to the engine.

It wastes money.

If fuel costs $4 a gallon, idling for 10 minutes a day costs $104 per vehicle per year. Even at $1.50 a gallon, you're still wasting $39 per vehicle per year.

It pollutes the air.

Vehicles emit many pollutants into the air. Compared to the smokestack image many people associate with air pollution, emissions from an individual car may seem insignificant. Emissions from many vehicles on the road or idling in a waiting area add up, however, and can have a serious impact on air quality.

It's harmful to our health.

Breathing elevated levels of air pollutants can adversely affect human health, especially in sensitive populations such as children, the elderly, and people with certain health conditions such as asthma.

It can damage our vehicle's engine.

Cylinders, spark plugs, and exhaust system are at risk. Idling an engine forces it to operate in a very inefficient and gasoline-rich mode that, over time, can degrade the engine’s performance and reduce mileage.

Is Your Business a Good Candidate?

Does your business have a vehicle fleet? Do drivers regularly let their engines idle for several minutes to warm up first thing in the morning? Do they leave vehicles running while loading or unloading or while conducting business? Does your business have a drop-off zone, drive-through window, or parking lot? If so, do customers frequently idle for 10 or more seconds on your property?

If any of these situations apply to your business, you're a good candidate for participation in the Clean Air Zone program.

Things Your Business Can Do

• Adopt a no-idling policy for your business and direct fleet drivers to turn off their engines while loading and unloading and parked. DEQ can provide you with suggested text and an easy-to-implement communications plan.
• Calculate how much you are spending on gas now and continue to track this expense over the next several months. Then show your drivers how much fuel costs have decreased as a result of curbing idling. Consider establishing an employee rewards program with the savings.
• Establish a clean air zone around your facility where idling is discouraged or not allowed.
• Post "Turn off your engine" signs in clean air zones to remind customers and vendors not to idle vehicles. You can obtain bright outdoor metal signs from DEQ that will capture drivers' attention as well as clean air zone stickers for drive-through windows.
• Publicize your participation in the program as part of ongoing company advertising.
• Consider purchasing fuel-efficient and hybrid vehicles for your fleet.
• Work with other businesses to encourage them to create no-idle zones at delivery areas, drop-off zones, and drive-through windows with typical wait times of over 10 seconds.