Per the AAMVA CDL Manual, approximately how far from the stop (or how many seconds before pulling over) should a school bus driver turn on the right turn signal when approaching an official stop?

AAMVA CDL Manual, Section 10.2.1 'Approaching the Stop,' p. 10-3; 49 CFR 383.123(a)(2)(i) (general topic only, no specific figures stated); 49 CFR Part 380, Appendix D, Unit D1.2

The turn signal is the second, closer-range warning in the sequence, telling traffic exactly where the bus will stop so drivers can judge following distance. Mixing up this timing with the amber-light timing is a common test trap and, in real driving, can shorten the warning traffic actually gets.