When approaching a school bus that is picking up or dropping off passengers you must?

If your state has the 8 light warning system, you treat a bus stopped just like a traffic light. If the yellow lights are flashing, you need to prepare for a stop. If you are too close to stop, you can proceed on through with caution. When the reds come on, you must STOP period.

When the reds come on, the bus driver has opened the passenger door to exit or pick up pupils.

If your state has the 4 light system (all reds), you must stop when they are activated.