You must stop for a school bus:

Question

You must stop when approaching a school bus that is displaying flashing red lights while stopped to pick up or drop off children. On a two-lane road, traffic moving in both directions must stop and remain stopped as long as the red lights near the top of the bus are flashing and/or the stop arm on the left side of the bus is extended.

Accepted Answer

If you are both driving on a two-lane highway and its red lights are flashing.

Answer

That is parked on the shoulder of the road with no one in it.

Answer

When it approaches you, even if its lights are not flashing.

Answer

Whenever the driver waves at you.

You must stop for a school bus:

Wait, before you go