What is idling? 

Idling is when your engine is running while your vehicle is not moving.

Where does idling occur?

Drivers mostly idle while waiting in drop-off/pick-up locations, drive-thru lanes and in traffic. School buses idle while waiting at schools, maintenance yards, and parking lots.

How is idling harmful to my health?

Increased air pollution from vehicle emissions is harmful to sensitive populations, including children, the elderly and those with respiratory health problems, such as asthma or chronic obstructive pulmonary disease (COPD). Idling is a source of diesel and gasoline emissions from the exhaust of the vehicles containing pollutants such as nitrogen oxides (NO_X), volatile organic compounds (VOCs), carbon monoxide (CO) and particulate matter (PM_2.5) that affect air quality and public health | Learn More >

Vehicle emissions are more concentrated at ground level which makes idling at schools especially a concern. Children have faster breathing rates so they tend to breathe more air per pound of body weight than adults. Also, while their lungs are still developing, children are more susceptible to developing asthma and respiratory and other health problems.

Why is idling costly?

Excessive idling can have significant cost burdens, including additional fuel and maintenance cost. Idling a car wastes up to 0.5 gallons of fuel per hour. Every year, school bus idling can collectively waste more than 3 billion gallons of fuel, costing more than $10 billion and leading to engine wear-and-tear and maintenance costs. School buses travel about 4 billion miles each year, providing safe transportation to and from school for more than 25 million children in the United States. 

How can I get involved? 

Currently, ADEQ is focused on promoting idle reduction on and near school campuses. School officials and transportation providers, parents and even students can play a major role limiting idling at schools. The Idle Reduction Program will be providing information and support to all schools to create healthier, cleaner air in their districts.

Launch an Idle Reduction Program at your school district | Learn More >

Is there help to replace an older school bus?

Yes, there are two grant programs that are available to school districts for school bus retrofit or replacement— one through the EPA and one through Maricopa County Air Quality Department (MCAQD). To learn more about the the grant programs, including application time frames and eligibility information, visit the following websites:

• EPA's Clean Diesel National Grants | Visit Page >
• MCAQD Clean Diesel Program | Visit Page >

In addition, the EPA offers a School Bus Rebate Program that typically opens the application process each fall. Visit the website for more information, including application time frames and eligibility | Visit Page >