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Air Quality in Indiana

Air Quality in Indiana > DieselWise > Public and School Transportation Public and School Transportation

How can school fleets minimize diesel emissions?

Why should school buses reduce idling?

Diesel exhaust from idling school buses poses a health risk to both students and drivers. When school buses idle outside school buildings, they emit exhaust fumes that can enter both the passenger compartments of the buses and the school buildings through ventilation systems. Scientific studies have concluded that exposure to diesel exhaust has many negative health effects including lung damage and respiratory problems. Although everyone is affected by diesel exhaust, children are most susceptible since their respiratory systems are still developing.

What are the benefits of less idling?

There are many benefits to reducing the amount of time that school buses idle each day. It helps protect the health of student passengers and school bus drivers. It reduces the air pollutants that contribute to high ozone and fine particles in a community. Reducing idling also saves money by lowering fuel consumption and reduces greenhouse gas emissions. In general a diesel vehicle burns approximately one gallon of fuel for every hour it idles. Less idling also saves on maintenance costs and increases the life of the engine.

What can bus drivers do?

All bus drivers should turn off their engines when they reach the school or other destinations, unless they will be leaving within a few minutes. Turning off the engine, instead of idling, while waiting for students will decrease the amount of diesel exhaust fumes released into the air. During morning start-up, buses should idle for the shortest possible duration necessary to bring the bus to proper operating temperature and to defrost the windows. There are times when idling may be necessary: the engine must be running to operate safety equipment, when the temperature is less than 32 degrees, or if a certain temperature must be maintained for students with special needs.

What can fleet operators do?

  • Install retrofit technology devices (such as diesel oxidation catalysts and/or diesel particulate filters) on their school bus fleet to reduce tailpipe emissions.
  • Use electric engine heaters to minimize idling time during warm-up.
  • Install a small generator or auxiliary power unit specifically designed for a school bus that provides heat, air conditioning, and/or electrical power while the vehicle is not in motion.
  • When buying new equipment, purchase engines already equipped with devices that minimize idling and warm-up time automatically.
  • Use cleaner burning fuels, such as biodiesel.
  • Assign the cleanest buses in the school fleet to the longest routes.
  • Inform bus drivers that parking and following other diesel vehicles too closely (caravanning) can contribute to higher concentrations of diesel exhaust inside and outside the bus.
  • Arrange bus departure times so that buses do not queue up for lengthy periods.
  • Examine the lay-out of the loading areas for each school. Re-configure to angle parking if possible.
  • Recognize drivers who successfully reduce idling.

What other things can school districts do?

  • Advise parents to turn off their vehicles when waiting to pick up or drop off children. The school district could distribute flyers or post signs on school property.
  • Prohibit delivery trucks from idling on school grounds. Advise delivery services of the no-idling policy and consider posting signs in delivery areas.
  • Consider urging your community leaders to issue a local idling reduction proclamation.
  • Consider using outreach materials to share your successes with other school districts, the media, and the general public.
  • Consider a program to educate children about the harmful effects of diesel exhaust.
  • Ask local businesses, non-profit organizations, parent/teacher organizations, etc. to donate gift certificates or other items to reward bus drivers who successfully reduce idling.
  • School districts should also make sure that indoor air intakes are not located near delivery areas. If they are, either change the configuration of the intake or change the delivery location, if possible.

School Transportation Association of Indiana (STAI) School Bus Idling Policy and Resolution (Statewide):

In cooperation with the School Transportation Association of Indiana (STAI), IDEM introduced a voluntary reduced idling program. This policy was unanimously adopted by STAI members at the annual conference in 2004. This policy can be implemented at any school system and/or municipality across the State of Indiana. Benefits of implementing this policy include: protecting the health of student passengers and school bus drivers, reducing air pollutants that contribute to high ozone in a community, reducing fine particles, and saving money by lowering fuel consumption and maintenance costs.

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