What must you do when a school bus ahead of you stops and extends its stop arm with red lights flashing?

When a school bus stops and activates its flashing red lights and extended stop arm, you must stop and remain stopped — in most situations in both directions — until the lights stop flashing and the stop arm is withdrawn, because children may be getting on or off and crossing the road. On a divided highway with a physical barrier, drivers on the opposite side may not be required to stop, but the rules are strict and vary, so caution is essential. Illegally passing a stopped school bus carries severe penalties and endangers children. Stopping for a school bus with flashing red lights is one of the most important rules of the road.