I know that where I live, a doctor can do something that makes the driver’s license folks have to hold a hearing on the individual. As far as I know, it’s almost never done because the doctor is going to 1.) be sued, and 2.) be dragged through the mud by the dipshit and nearly every single person who knows the dipshit. For most, it’s just not worth it.
Which was a commercial failure, if anyone is curious. The whole shebang lasted less than two years. Started in 1860, bankrupt in 1861, thanks to the telegraph’s stretch across America.