We are WAY past the point where upgrading our public transportation should have been a priority. In fact, instead of solving the problem with better public transportation things like Uber etc have filled the gaps, but still basically mean cars on the road.
It shouldn't be that hard for a person to get just about anywhere in the US at this point with public transportation. High speed trains from each major city to another should be the norm, with options between taking a train with stops (but takes longer of course) or taking a non-stop train that gets there faster then you could drive.
Meanwhile the bus system should have been drastically upgraded and supported, instead of spending so much money on making it possible for more and more cars to drive everywhere. You should be able to catch a bus just about anywhere in a populated area within 10 minutes, and the cost to ride buses/trains etc should be drastically reduced. It should not be a for profit situation, but again, should be like our roads, taxed enough to pay for it all, so everyone can get around easily.
Add in easily used lanes for scooters and bicycles (max 15 mph), to allow people to easily get around in cities etc, and the number of cars needed, let alone actually being used on a regular basis would plumit.
But that would hut the auto industry which has tons of money and so it will never happen. Even though it would be better for everyone, the environment, cost less money, and drastically reduce deaths each year.
So yeah...forget about having people retake the test, focus on making them NOT NEED TO DRIVE!
Most people are not going to take public transportation just because it happens to be there. ---