A new analysis highlights the role of existing and emerging fuels and technologies in powering the nation’s transit bus, school bus, and commercial truck fleets.

“It’s a very dynamic time for fuels, technology and mobility and it is important to understand which technologies are powering these sectors today to better inform our understanding and in making decisions about the future,” said Allen Schaeffer, executive director, Diesel Technology Forum (DTF).

Diesel is the predominant technology in commercial trucking, school, and transit bus sectors, according to the DTF’s analysis of data sourced from S&P Global Mobility TIPNet data of vehicles in operation for Class 3-8 as of December 2021. The analysis found:

Transit Buses: 79% of all non-school (transit) buses in operation are powered by diesel, 10% compressed natural gas, electric (6%), other (5%) and gasoline (0.1%). The “other” category includes hybrid diesel electric as well as propane-powered buses.

For the diesel portion of the current fleet, about 59% of transit buses are at least equipped with particulate trap technology and 47% are the newest generation of advanced diesel technology equipped with both particulate filters and selective catalytic reduction systems.

New Jersey is the state that added the newest generation diesel buses in 2021 (more than 300) compared to the previous year. Washington D.C. saw a 15.3% increase in number of new diesel buses put in service (2021 vs. 2020).

School Buses: 91% of the approximately 500,000 school buses run on diesel power. Other fuels that play a role in pupil transportation include gasoline (4%) and other fuels (5%). Electric and compressed natural gas each register less than 1%.

Of the diesel portion of the current school bus fleet, approximately 72% of all buses in operation have at least particulate trap technology and 58% are of the newest generation of advanced diesel technology equipped with both particulate filters and selective catalytic reduction systems.