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Air Quality in Indiana

Air Quality in Indiana > DieselWise > Public and School Transportation  > STAI School Bus Idling Policy STAI School Bus Idling Policy

The Student Transportation Association of Indiana (STAI), working in partnership with the Indiana Department of Environmental Management has developed a school bus idling policy. For the health of our children, and to help improve air quality, STAI strongly urges its members to immediately implement this voluntary policy.

During morning start-up bus will idle no longer than the allowed time limits for the following temperatures:

  • 32 degrees and above five (5) minutes
  • 20 degrees to 32 degrees fifteen (15) minutes
  • From 20 degrees and below, buses will be allowed to idle for up to thirty (30) minutes; or until front windows are defrosted and all safety equipment is operable.

Drivers will turn off engines after an appropriate cool-down time upon arriving at their destinations to load or unload students. This applies to home to school or field trip activity.

We urge all member school districts to adhere to this policy for the following reasons:

Emissions from diesel engines are significant sources of toxics such as nitrogen oxides (NOx) and fine particulate matter (PM). Vehicle exhaust is linked to increased rates of cancer, heart and lung disease, asthma and allergies. Studies have concluded that emissions from vehicle exhaust are hazardous to human health, especially children. Children breathe more rapidly and inhale more pollutants per pound of body weight than adults. In addition to the health risks, NOx and PM also contribute to ozone, commonly referred to as "smog," that can be transported long distances, and affects an area's ability to meet the health standards for ambient air.

Emissions from idling school buses are emitted at ground level where children may inhale them or the emissions may be drawn into the school's ventilation system. Bus idling and bus queuing (back-to-front line-up of buses) also increases the concentrations of harmful particulate pollution inside school buses.

The elimination of air pollutant emissions is all of our responsibility and we all want to contribute to this important endeavor.

While we cannot control unnecessary idling by other motorists in and around our school parking lots, we can do our part to reduce emissions by instructing our drivers to turn off their buses as soon as they arrive at their destinations, and not to restart them until they are ready to resume travel.