The company also launched a new sustainability reporting feature for school districts.
The Georgia-based school bus manufacturer will continue working with Ford Component Sales and Roush CleanTech until at least 2030.
Some administrative hurdles remain, but the shift could result in marijuana's acceptance as a Schedule III drug under the U.S. Controlled Substances Act and might bring changes to federal drug-testing laws.
The six buses are the first deployed in Pennsylvania with funds from the U.S. Environmental Protection Agency's Clean School Bus Program.