[onewhippedpuppy]

One thing worth considering, losing his license doesn't mean that he has lost the ability to drive, only his legal right to do so. If you don't take his keys there's still the risk that he could choose to go out for a drive on his own, the law be damned.

My parents had to make this decision with my grandmother a few years ago shortly after my grandfather died. She put up a fight until they made the point that their concern was she would kill someone else, not herself. Put in that context she "got it" and gave in, albeit with some grumbling. She now lives with them and bought a van for them to drive her around in so she could be comfortable.