Roof hatches: Question Roof hatches: Answers Must be removed before a bus is driven. Must be closed before a bus is driven. May be locked in a partly open position during a drive. May be removed during a drive. Explanation On a bus, it is acceptable to lock some roof hatches in a partially-opened position to provide fresh air, but this should not be made a regular practice. Remember that opening these hatches will slightly increase a bus's clearance.
