The Yellow Footprint


According to the American School Bus Council, riding a school bus takes, on average, about 36 passenger cars and trucks off of the road. But how does that translate into reducing the overall carbon footprint?

To find out, we enlisted the help of Dr. Joseph Schwieterman, director of The Chaddick Institute for Metropolitan Development at DePaul University in Chicago.

Schwieterman, who is a regular contributor to the Transportation Research Board and an author of several articles and books on economic development and transportation planning, authored a recent study that was publicized in the news media and by the American Bus Association Foundation. This study demonstrated why doubling or tripling the market share of intercity buses would be a far easier way to achieve the same fuel reduction as offered by the use of hybrid cars, public transit use and bicycle commuting.

In studying school busing in the United States, he made several assumptions based on data provided by the American School Bus Council, namely that 480,000 school buses are in service each school day transporting 25 million students one way. Based on an average school year of 180 days, he figured that 400 school bus boardings per student occur each year, and each school bus provides 54 unique trips per student served each day. He also assumed that about 5 million students also ride on field trips or activity trips each day. This all equates to more than 13 billion estimated school bus trips a year. He further assumed that the occupancy on school buses averages 15 students per mile driven, which includes an adjustment for empty miles to service/storage. He then compared the average school bus mpg of 6.5 with that of cars, 25 mpg.

The results, again, while based on many assumptions to take into account the wide spectrum of school bus operations, were eye-opening. At just over 15 billion per year, the nation’s fleet saves more than 35 billion pounds of carbon emissions, nearly 18 million tons, when compared to driving students in personal vehicles and taking public transit to and from school. Without school buses, parents, teens and other motorists driving kids to school would generate carbon emissions at nearly 49 billion pounds — more than three times than what is generated by school buses. Schwieterman’s calculations also determined that school buses move passengers at almost twice the fuel efficiency as that of transit and almost five times that of personal vehicles. In the absence of school-bus service, the amount of fuel consumed would rise more than three-fold to more than 2.2 billion gallons per year.

“Part of the reason is that many parents driving their kids to school return home without passengers, wasting precious fossil fuels in the process,” Schwieterman added.

Download the school bus calculations.