Vehicle Idle Reduction


Pima County Idle-Free School Program  school idle sign

Pima County schools are encouraged to join the 2022 Idle-Free School Program to reduce student's exposure to toxic air pollution emitted by motor vehicles.

Air monitoring at schools has shown elevated levels of toxins during pick-up times as parents idle their cars while waiting for their kids. Exhaust fumes from cars are linked to increases in asthma, allergies, heart and lung disease, and even cancer. Children are especially at risk because their lungs are still developing and they inhale more air per pound of body weight. 

How can schools participate? PDEQ is committed to supporting schools in implementing their Idle-Free School efforts by providing participating schools with:

  • Signs that can be placed in drop-off and pick-up locations at the school
  • Sample letters to parents, delivery drivers, and bus drivers
  • Idle-free bookmarks and static-cling decals for parents/guardians
  • Guidance on how to create student-led Idle-Free School campaigns
  • Sample Idle-Free School policies

Check out and share our IDLE LESS video.

See our IDLE LESS bookmark.

To sign up for the 2022-23 Idle Free School Campaign, complete this Idle-Free Zone application. After registration is complete, the designated school representative will be asked to schedule a 30-minute meeting with PDEQ Clean Air Program staff to walk through the steps of implementing the program and answer questions.

Idle-Free Business Program

Pima County businesses are encouraged to be idle-free. Idle-free businesses commit to implementing an idle-free policy and place idle-free signs in their parking lots. The PDEQ Clean Air Program will provide 2 idle-free signs per business free of charge.

For more information contact:

Natalie Shepp

FACT IS…Idle Reduction Drawing

► U.S. EPA found elevated levels of benzene, formaldehyde and other air toxics at schools that coincide with parents picking up children from school.

► Idling engines produce thousands of tons of toxic pollution each year.

► Children are still developing and are physiologically different than adults. Children have higher respiratory rates, faster heart rates, and thinner skin.

► Children may be exposed to air pollutants more because they tend to be outdoors more and are often very active when they are outdoors.

► Studies have linked various negative health outcomes in children exposed to vehicle pollution, including:

  • Reduced lung function;
  • Respiratory infection;
  • Decreased cognitive performance;
  • Reduced language abilities;
  • Asthma symptoms; and
  • Chronic respiratory symptoms.


Fact Is...Don't make me cough

► Idling for 10 seconds uses more fuel and emits more greenhouse gases than restarting the engine.

► Vehicles warm up faster when driving than they do when idling. Drive slowly at first and avoid revving the engine.

► You will protect your car engine if you idle less. Idling can cause damage to engine parts like cylinders, spark plugs, and the exhaust system.

► Only the battery and starter are affected by frequent starts, but the cost of this wear-and-tear is well below the fuel-cost savings of shutting off your engine.

► In some cities, like Boston, it is against the law to unnecessarily idle a vehicle and it is punishable by citations and fines.

You can reduce vehicle idling and still maintain your comfort with these simple season-based action items:

Spring/Summer: Keep Your CoolFor healthy air

► Park your vehicle in the shade and walk to a cool area while waiting.
► When parked outside, leave windows open a crack to allow hot air to escape .
► Use a sun shade in your windshield when parked to reflect sunlight and heat.
► When driving after being parked outside, open your windows for a short time to allow the hot air to escape. You'll feel the cool air from your air conditioner quicker.

Winter: Avoid Ice Build-Up & Warm-Up Idling

► Park in garage or under carport if available.
► Cover outside of windshield with sunshade or hang towels on windows overnight.
► Keep warm inside your vehicle with a jacket and gloves.

Spring & Fall:

► Roll down windows and enjoy the mild or warm temps while your engine is off.
► Much vehicle idling is simply done out of habit. Break the idling habit - Fix the air!


Different vehicles consume fuel at different rates when idling. From U.S. EPA Idle Free Schools Program:

Vehicle Type 

Idling fuel use (with no AC or radio running)

Light-duty passenger car

0.0053 gal/min

Light-duty pick-up trucks, SUVs, minivans

0.0118 gal/min

How many minutes do you idle in one school year?
15 min./day  x  180 school days/yr  =  2,700 minutes of idling per school year

How much fuel does that idling consume?

2,700 min/yr  x  0.0053 gal/min  =  14.31 gallons of fuel per year in a passenger car
2,700 min/yr  x  0.0118 gal/min  =  31.86 gallons of fuel per year in a pick-up truck, SUV or minivan

How much air pollution does that idling vehicle emit?
For every 1.17 miles driven, about 1 pound of pollution and greenhouse gases are emitted (Pima Association of Governments, 2017). Assume a person can drive 7 miles in 15 minutes in a school neighborhood.

2,700 min/yr  x  7 mi/15 min ≈ equivalent of driving 1,260 miles
1,260 mi x  1 lb/1.17 mi  = 1,077 pounds of pollution and greenhouse gases per school year
Dirty air

RainbowSchool Pocket Parks can give a reason for parents to not idle their vehicles while waiting to pick up their children from school. With less idling vehicles on school grounds, the air will be healthier to breathe.

A School Pocket Park can be a small area on school grounds that can be used for relaxation, enjoyment, learning, volunteering and promoting a stronger community. They can act as outdoor classrooms, meeting spaces or areas for parents to network or volunteer, They can incorporate shaded areas, seating, a Little Free Library, community garden, or even a work area where parents can help with simple teacher tasks.  Your School Pocket Park can be what the school, its students and community can imagine!

Ideas and Resources:
Pocket Park flyer developed in collaboration with a UofA College of Public Health student intern.
► Establish a No-Idle Zone: Idle Free Schools Programs and free toolkit at ADEQ and U.S. EPA.
► Plant low-cost shade trees: Trees for Tucson, Trees for You.
► Install free bike racks: Tucson's Bicycle and Pedestrian Program.
► Develop a Little Free Library with book donations from the community and/or Literacy Connects .
► Use the space as an outdoor classroom.
► Engage classes by assigning art or science projects for the outdoor space.
► Provide benches and tables for visitors or students to gather at for conversation or lessons.
► Plant low-maintenance native vegetation that attracts butterflies or build nest boxes for desert birds.
► Visit the Tucson Audubon Society for educator resources or volunteer opportunities.
► Make a Zen Garden or Peace Garden as a setting for quiet reflection or service learning.
► Install a shade canopy or ramada to protect people from the sun.
► Reference the Watershed Management Group for ideas on rainwater harvesting
► Offer students leadership opportunities and hands-on ecology education with a school community garden. Manzo Elementary is a great example. Community Gardens of Tucson provides planting guides and resources.
► Use your student council, honor society or other engaged student group to develop and maintain the space. Perhaps even your students' parents would lend a hand as they wait for their students at the end of the school day. Utilize service groups to help plan and install your features:


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Department of Environmental Quality

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Tucson, AZ 85701

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