School Bus Idle Reduction Strategies

No-idle zone sign

School bus idling leads to wasted fuel and increased emissions. This can have negative health impacts for those near the buses, especially schoolchildren.

As a general rule, bus engines should be turned off immediately after arriving at loading or unloading areas. The school bus should not be restarted until it is ready to depart, and during early morning warm-ups, idling should be limited to the manufacturer’s recommendation (generally no more than five minutes to warm the engine). Additional heat, provided by auxiliary equipment, may be required to warm up the passenger compartment.

The U.S. Environmental Protection Agency (EPA) developed the Clean School Bus Program to reduce school bus idling. This campaign:

  • Provides an opportunity for bus drivers, transportation managers, school administrators, teachers, parents, and children to learn about air quality and diesel emissions
  • Recognizes the positive contributions being made by school bus drivers
  • Promotes idle reduction as an easy way to save money by saving fuel, reduce engine wear and tear, protect the health of drivers and children, and improve air quality.

School Bus Idle Reduction Technologies

For school buses (and transit buses) that operate in cold climates, fleet managers have a few limited options to reduce idling time through technologies that pre-heat cold engines or provide an independent source of heat for the cabin. Supplemental diesel or electric block heaters can be effective at helping with cold starts, but such technologies may only provide limited warmth to the cabin without the aid of the bus engine. Though less common, stand-alone heaters, such as the Webasto Air Top heater, can also warm or retain heat in the passenger compartment without idling. Additionally, electric transit buses sometimes use roof-mounted diesel heaters during the winter as an independent source of cabin heat, which could be a viable technology for school buses as well. The EPA has more information available about these idle reduction technologies.