Final answer:
Pulling over to allow an emergency vehicle to pass is both common courtesy and often a legal requirement, ensuring quick and safe passage for responders.
Step-by-step explanation:
When driving at night and being passed by an emergency vehicle, common courtesy and legal requirement in most places dictates that you should pull over to the side of the road and stop, becoming stationary until the emergency vehicle has passed. This action ensures that the emergency responders can get to their destination quickly and safely. You should do this as soon as you hear the siren or see the flashing lights, using the Doppler shift of the siren sound to gauge how close the emergency vehicle is. Once it has safely passed, you can resume driving.