Older Drivers

When do you say that's enough.I saw several older drivers yesterday going down the road at 5 to 15 miles an hour. Some could barely see over the steering wheel. One older woman stopped about 4 car lengths from a stop sign and then just drove on through it and cut off the other drivers that didn't have to stop. You know how people say " she gets around really good for her age and doesn't need help ". When she gets hit and hurt or hurts someone else do you think someone will say that's enough?