Final answer:
You must stop for a stopped school bus picking up or letting off children and may not pass it. This traffic law is in place to protect the safety of children and applies in most countries, with specific regulations varying by location.
Step-by-step explanation:
The speed at which you can pass a school bus that is stopped to pick up or let off children is effectively zero because it is illegal to pass a stopped school bus in this situation. School buses have flashing red lights and a stop sign that swings out to warn drivers that children are crossing the road. The laws vary by country and state, but in the United States, all states require drivers to stop for stopped school buses when the red lights are flashing.
In situations where a school bus is on the opposite side of a divided highway with a median separation, some states allow vehicles on the other side to continue without stopping. However, when driving on an undivided road or when the school bus is on your side of the road, you must come to a complete stop and cannot proceed until the school bus starts moving again or the bus driver signals that it is safe to pass.
Passing a stopped school bus illegally can lead to severe fines or more serious consequences, especially if a child is endangered. Always follow traffic laws and ensure the safety of school-aged children.