did some more checking in your location RSDR stands for Road Sign Detection and Recognition. sometimes ambulance paramedics have to shack to see if the patients vision is being affected by drugs/ alcohol or medical condition. they use the road sign detection and recognition test to find out by asking the patient to follow an object and ask the patient if they can see something across the room, sometimes they draw a road sign on a paper and ask the patient if they know what that picture is. Im guessing that when they did that with your mother she got angry\ verbally abusive and threatening manner.