ELDT training curriculum under 49 CFR Part 380, Appendix D requires school bus driver training to cover mirror types and use in connection with which federal motor vehicle safety standard?

49 CFR Part 380, Appendix D, Unit D1.1; FMVSS 111 'Rear Visibility' (49 CFR 571.111)

Knowing that mirror requirements trace back to a specific federal safety standard (not just manufacturer preference) underscores that mirror placement and function on a school bus are legally mandated minimums, not optional comfort features.