When preparing to leave after unloading students at the school, what must the driver do that is not part of the departure sequence after a route stop?

AAMVA CDL Manual, Section 10.2.4 – Unloading Procedures at School, p. 10-5 (July 2017 revision); 49 CFR §383.123(a)(1)

Because the school-unloading procedure has the driver fully shut down the bus (ignition off, possibly leaving the seat), restarting it requires extra steps that a quick route stop never needs, like buckling in and starting the engine before moving. Recognizing which steps only apply after a full shutdown helps a driver follow the correct checklist instead of skipping something needed to safely get underway again.