After a student begins crossing on the driver's first signal, what must they do upon reaching the left edge of the school bus?

AAMVA CDL Manual, Section 10.2.3 'Unloading Procedures on the Route' (subsection: Additional Procedures for Students That Must Cross the Roadway), pp. 10-4–10-5 (July 2017 revision); 49 CFR §383.123(a)(1)

Conditions can change in the few seconds it takes to walk across a roadway, so the manual builds in a second stop-and-signal checkpoint at the far side of the bus rather than treating the crossing as one continuous motion. That second pause gives both the driver and the student one more chance to catch an oncoming vehicle before the student steps clear of the bus's protective view.