What kind of disabilities are we talking about? Because I’m pretty certain that to a blind person a car won’t help them much, and in fact probably makes life in general more dangerous. Further poor people who have a mobility impairment are often forced into dangerous situations, such as operating a motorized wheel chair in mixed automobile traffic instead of being able to use a dedicated bike lane (yes I’ve seen this many times).

EDIT: I'm not saying wheelchair-bound and other similar people should be banned from driving. Like today, we can add wheelchair-only parking accommodations. In fact, restricting traffic to only people with a genuine need will make their trips faster.