@woojr -- I'd bet you know your mom better than anyone. Based on your informal assessement of her physical / mental capacity, at the very least, I think I'd also want a true assessment by experts of my mother's actual abilities. This would include getting both a cognitive test covering the rules of the road; a physical, behind-the-wheel and in traffic assessment by a professional instructor; and even her GP's medical opinion of her functional level, strength, response time, hand / feet coordination, and a vision test.

Here in FL, I believe a close family member can informally request the DMV to follow up on a concern with respect to seniors of a certain age. The request may be asked to be handled anonymously. Companies and individuals here that complete the driving assessment must be trained and licensed. While our DMV also undertakes "minimal eye tests" through our driving years, it may further request, based on a professional's recommendation, that a more comprehensive vision exam be undertaken.

Of course, the goal of the above is to safeguard the life of the senior driver... AND the general public... while allowing a driver the opportunity to demonstrate her / his continued safe driving skills.

All the best!

/LarryG