An emergency roof hatch: Question An emergency roof hatch: Answers May be left partially open while traveling to allow for the movement of fresh air. Should only be open during an emergency. Should always be open. Does not need to be locked. Explanation When operating a bus, you may sometimes open a roof hatch partway to bring fresh air into the vehicle. However, it is not a good idea to make this a regular practice. Opening a hatch will slightly increase your bus's clearance.
