On the way loading students, when should the driver activate alternating flashing amber warning lamps?

A If the school bus is so equipped, activate alternating flashing amber warning lamps before the school bus stop in accordance with state law.

explanation

If the school bus is so equipped, activate alternating flashing amber warning lights at least 200 feet or approximately 5–10 seconds before the school bus stop or in accordance with state law. [Commercial Driver Handbook]