When I take Dad to the ER (which unfortuantely, is a fairly common occurence), I go to the ambulance area. There are 5 slots, with the door at one end. I park at the far one (in slot 5), get Dad in, tell the receptionist he is there (even though she always scowls at me because I am supposed to wait in line and I am interrupting her interveiw of the person she is sitting with) and go move the car.

That is what one hospital does. At another hospital, you have to park and "hike" to the ER. They said that if you don't need an ambulance, you can hike in. They actually prefer that you take an ambulance, and also, you get seen to immediately when you arrive in ambulance.