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Arizona Department of Environmental Quality Arizona's Official Website
Arizona Children's Environmental Health Program: School Vehicle Idle Reduction Program

The School Vehicle Emission Reduction Program is part of the Arizona Department of Environmental Quality’s (ADEQ) Office of Children’s Environmental Health (OCEH) efforts to reduce environmental risks to children's health.

ADEQ has worked with school districts across the state to adopt idle reduction practices and provide a model bus idling policy for schools to use. Key elements of the policy include turning bus engines off when reaching the school, not turning on the engine until ready to depart, establishing a bus loading zone at least 100 feet from the schools air intake system, and posting signs advising drivers to limit idling at or near schools. Since the program started in 2004, 167 school districts from all 15 counties in Arizona have joined this voluntary program to reduce bus idling and limit children’s exposure to diesel emissions. ADEQ is presenting an overview of the program to other school districts for consideration and offers technical assistance to districts that request it.

View the bus idling video and learn more about why school bus idling reduction is so important.

Why Idle Reduction Matters

Unnecessary school bus idling affects human health, pollutes the air, wastes fuel, and causes excess engine wear. Fortunately, it's easy to implement practices that reduce school bus idling.

Health Impacts

Idling school buses can expose school children to diesel exhaust on a daily basis. Diesel emissions can aggravate respiratory illnesses such as asthma and have been linked to heart and lung disease.

Air Pollution

Idling school buses can pollute air in and around the bus. Exhaust from buses can also enter school buildings through air intakes, doors, and open windows. Diesel exhaust contains pollutants that contribute to ozone formation, haze, and acid rain. Fine particles from diesel engines contribute to haze which restricts our ability to see long distances.

Wasted Fuel and Money

Idling buses waste fuel and money. When idling, a typical school bus engine burns about half a gallon of fuel per hour. School districts that eliminate unnecessary idling can have significant savings in fuel costs each year. Use the U.S. Environmental Protection Agency’s Fuel Savings Calculator to estimate the fuel and money saved by reducing idling in your school bus fleet.

Engine Wear-and-Tear

School bus engines do not need to idle more than a few minutes to warm up. In fact, extended idling causes engine damage. Engine manufacturers generally recommend no more than three to five minutes of idling.

ADEQ’s School Vehicle Idle Reduction Initiative

Have you ever left your car running while you waited to pick up your children, or while you waited in the drive-through lane at your bank or your favorite drive-through restaurant or coffee shop? Have you ever left your vehicle idling in the morning? Most of us have. But when you leave your vehicle running while parked or sitting still, the engine produces air pollution. This pollution contributes to poor air quality and harms human health.

A great deal of idling takes place at schools, not just from school buses, but from parents waiting in lines to drop off and pick up children before and after school, and also from delivery trucks. Limiting unnecessary idling is an easy way for schools and the public to contribute to improved air quality and reduced vehicle emissions at schools. Since the school vehicle emission initiative began in 2009, 41 schools and community centers have joined the program, posting signs and making the commitment to create no idling zones. Participants are asked to educate the entire school community and public visitors using the letter templates and the idling and pollution fact sheets from the toolkit. OCEH also attends neighborhood festivals, community health events, and school education group events to hold direct conversations about idle reduction practices with the public. OCEH currently promotes the Environmental Protection Agency Programs (Region 8) idle free schools student and teacher involvement component when working with teachers or parent teacher groups. Involving the students, teachers and parents in a vehicle emission reduction campaign can help your school implement a successful idle reduction program.

ADEQ provides a free accessory program to assist with educating the community. The ADEQ Air Quality Flag Program uses nautical-style flags to serve as a visible reminder of what air quality is projected to be for any given day. The flags create the public awareness of outdoor air conditions so people can modify their behavior to reduce exposure to air pollutants. School district transportation directors have used the flag program and the health recommendation guidance during Health Watch Alerts and High Pollution Advisories, to remind drivers to follow the no idling guidance. Limiting our idling especially during unhealthy air quality conditions is an easy way we can all “take action” to reduce vehicle emissions, improve air quality and protect public health.

No Idling Program Tool Kit

Create your own vehicle idle reduction program using our free, ready-to-use, downloadable materials. Use “as-is,” or modify for your own no-idling reduction campaign.

Helpful Links

Grants and Funding

Clean School Bus Idle Reduction Campaign

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