U.S. transit bus fleet fuel types 2013-2019
Diesel was the leading fuel type for transit buses in the United States between 2013 and 2019, representing 41.8 percent of the fleet in 2019. By contrast, diesel made up 56.3 percent of the total bus fleet in 2013. Natural gas vehicle registrations were on the rise during this time period, reaching around 21,486 units in 2019. Hybrid buses were the second most popular category of alternative fuel buses, decreasing to just under 13,000 that same year. Transportation represents around 29 percent of the U.S. greenhouse gas emissions.
