Hi, Ahands ... good point about when to stop driving. I have a copy of the AAA senior drivers test (it's an interactive disk) which I take every year and have been doing since before I had symptoms of ALS.
I took it this morning, and it showed no impairment in any of the areas it tests: leg strength and general mobility, flexibility in moving head to see behind you, reflexes, cognitive ability (spotting cars/trucks in various parts of the computer screen, identifying their positions and identifying the kind of vehicle, etc), peripheral vision, decision making and lots more.
All this is good. It gives me one less thing to worry about right now ... but what it doesn't measure is what I have already detected weakness in, which is arm strength. I have no trouble steering the car when it's moving, but when the car is BARELY moving, such as in parallel parking or backing out of a parking place, it's a job for me to turn the steering wheel. Fortunately, when I'm parking or backing out and the car is going one mile per hour, I'm unlikely to hit anyone!
But I know the arm weakness will get worse, and even though the AAA test continues to show "no impairment in driving abilities" I may have to overrule it.
This is always a difficult decision for older drivers, ALS or not.