How must carry-on baggage be handled so it does not endanger passengers?

Carry-on baggage must be stowed so it never blocks the aisle, the entrance, or any emergency exit, and so it cannot fall and injure a passenger during braking or a crash. Aisles and exits must remain clear at all times in case the bus must be evacuated quickly. The driver should make sure items are placed in overhead racks designed for them or otherwise secured, and should refuse or rearrange baggage that creates a hazard. Keeping the aisle and doorways open is a safety requirement, not just a convenience, because passengers may need to move fast in an emergency.