When are other vehicles required to stop for a school bus with red lights flashing and stop arm extended?

On an undivided road, all traffic in both directions must stop when a school bus has red lights flashing and stop arm extended — this protects students who may cross the road. On a divided road (with a physical median or barrier), generally only traffic in the same direction as the bus must stop; traffic in the opposite direction continues at normal caution. Specific rules vary by state. The penalty for illegally passing a stopped school bus is severe in every state — often $250-$1,000 first offense, license suspension, and points. Drivers should never assume; come to a complete stop until the red lights stop and the stop arm retracts.