Never had to call 911, but since my wife is an md who used to do a lot of call in a rural area, we've had the ambulance stop in our driveway to pick her up...also, one famous new years eve, when our plumber (!) stopped by at 11pm, with his unconscious son in the backseat of his car.....son was at a party, he passed out, they called the parents, who went to get him; they were on their way to the hospital, but saw our lights on.....my wife went out to check on him, then we called the ambulance.....it's fun having all of this going on in your own driveway.....