Let’s assume we’re not stopped at a traffic signal.
This is only anecdotal, but I heard once that you’re not supposed to stop altogether, rather drive at a slower pace so as to let it pass quickly. The person said what was more important is that drivers don’t make sudden changes to their behavior. An EMT driver can more safely maneuver if they don’t have to predict what any one knucklehead will do the moment they get close.
If this is wrong or needs clarification, please enlighten me!
“Supposed to do” is kind of vague, but many people have answered the “legally required to do” already.
If you or someone you love dearly were in an ambulance heading to the hospital to deal with an emergency medical condition (or waiting for one to arrive & provide transport to the hospital), what would you want everyone in the path to do? Whatever the answer to that is, do that. For me, the answer is, “as quickly and safely as possible make a path for the ambulance.”
Is that pulling over? Stopping? Pulling into a parking lot? Continuing to drive until one of those options is available? Depends. Are you on a crowded road with no way to pull over? Then stopping will impede the ambulance. Don’t impede the ambulance. Are you the only car on the road? Then slow down and move to the right (in the US).