I'm scared of my 87 year old Mother driving and getting lost or causing an accident

Backgroud: my mother has significant short term memory problems, is underweight (97 pounds), and has kyphosis (head is always hunched forward). But her vision is mostly good. She has a strong personality where she does not want others to help her. She can get agitated if you disagree with her and sometimes her temper will flair.

A couple weeks ago, my mother was backing up out of a parking lot and hit another car. I am not surprised, since she doesn't have very good mobility with her neck to look behind.

Recently my mother would rarely drive, but when she did, my father always guided her and helped her remember where they were going. This month, my father had an accident and living in long term care. My mother is now living alone and refuses to consider living in an assisted living community.

After my father's accident, we hid the car keys and have been explaining that they are "lost". She isn't happy with this, but it is working for now.

Every time I talk about quitting driving, she gets upset. "I've been driving since I was 12". "I'm a really good driver".

This is so stressful to keep up this charade. I'm not sure how much longer it can go on.