In this LIVE stream training, AFS Founder Thomas DeVore breaks down the federal laws associated with mask requirements on public transportation. According to [USC02] 49 USC Ch. 53: PUBLIC TRANSPORTATION, school bus service is NOT defined as public transportation.
[USC02] 49 USC Ch. 53: PUBLIC TRANSPORTATION
(15) Public transportation.—The term “public transportation”—
(A) means regular, continuing shared-ride surface transportation services that are open to the general public or open to a segment of the general public defined by age, disability, or low income; and
(B) does not include— (i) intercity passenger rail transportation provided by the entity described in chapter 243 (or a successor to such entity);
(ii) intercity bus service;
(iii) charter bus service;
(iv) school bus service;
(v) sightseeing service;
(vi) courtesy shuttle service for patrons of one or more specific establishments; or
(vii) intra-terminal or intra-facility shuttle services.