Clean and Green School Buses

This fact sheet from the Environmental and Energy Study Institute (EESI) examines the environmental and health impacts of school bus transportation, highlighting the benefits of buses over private vehicles and the specific dangers associated with diesel engine idling.

• School buses significantly reduce environmental impacts by displacing private automobile trips. Based on data from the Massachusetts Department of Environmental Protection, assuming one school bus replaces 20 private vehicles, there is an 80 percent reduction in oil consumption and carbon emissions, a 60 percent reduction in carbon monoxide, and a 50 percent reduction in nitrous oxides. A fleet of 500,000 buses transports 25 million U.S. students daily, covering approximately 4.3 billion miles annually.
• The practice of idling diesel engines in school buses—which power 95 percent of all school buses—leads to wasted fuel and increased pollution. An idling diesel bus uses about one gallon of fuel per hour. Nationally, truck and bus idling consumes roughly 2.4 billion gallons (56 million barrels) of diesel fuel annually, representing 2-3 percent of total annual U.S. diesel consumption.
• Diesel exhaust, particularly particulate matter, poses severe health risks to children, who are more susceptible than adults because they inhale 50 percent more air per pound of body weight. Health impacts include triggered asthma, exacerbated pneumonia and bronchitis, decreased lung function, and airway inflammation. Diesel exhaust is identified as a possible human carcinogen and a cause of premature death.
• To mitigate the risks of idling, the document suggests educating drivers and officials, using auxiliary heaters to remove the incentive to idle, and routing traffic to keep drop-off areas away from buildings. Additionally, the Utah Clean Cities program has created a clean school bus and idle reduction curriculum for local school district employees, which has been tested in six districts.

APA

Mueller, J. (2008). Clean and Green School Buses. Environmental and Energy Study Institute. https://www.eesi.org/files/school_bus_factsheet_102108.pdf

Chicago

Mueller, Jan. Clean and Green School Buses. Environmental and Energy Study Institute, 2008. https://www.eesi.org/files/school_bus_factsheet_102108.pdf.

Wikipedia

{{cite report |last1=Mueller |first1=Jan |title=Clean and Green School Buses |publisher=Environmental and Energy Study Institute |date=21 October 2008 |url=https://www.eesi.org/files/school_bus_factsheet_102108.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{mueller2008clean, author = {Mueller, Jan}, title = {{Clean and Green School Buses}}, institution = {Environmental and Energy Study Institute}, year = {2008}, month = oct, url = {https://www.eesi.org/files/school_bus_factsheet_102108.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }