I've stopped a couple times for accidents (as a lay nobody) and been surprised by the proximity of nurses. Just this past St. Patrick's Day a drunk blew a red light and caused a nice wreck. I was passing by and pulled over (I only do this when there are no flashing lights yet on the scene), only to see two nurses already working on the soused patient (the young lady he t-boned was fine, fortunately). I was happy to just hand out gloves and gauze and hold the flashlight while they worked. It's been almost 20 years since my last first aid course, so I was glad to have professionals on the scene and not be hands-on myself.