I just heard an NPR segment on the issue of elderly drivers the other day, and I was shocked by the attitudes that many of the guests (including government officials) expressed. There were a lot of claims that the elderly are "just as safe" as younger drivers because they don't take as many risks (probably true, but irrelevant, because that's a really low bar given how much most Americans suck at driving). They said that there should be NO age at which higher testing requirements, etc kick in (and even opposed a state legislator who wanted to require retesting every 5 years after age 85), because they said that lack of driving ability is caused by physical conditions, not age. While that's true, those age-related conditions are more common the older you go, and all that was being proposed was retesting, not just yanking their licenses.
Some of the program guests also were opposing doing anything to expand drivers' license testing on two grounds: first, that we can't take people's drivers' licenses away even if they are incompetent to be on the road, because that would rob people of their independence and put them in "house arrest", and second, that it would be too costly to implement more effective road testing for all drivers of all ages because it costs so much money to administer such a test. I find the first point ridiculous since there are any number of options people can use to get around other than driving themselves (although I'll grant that many areas, especially rural ones, have limited low-cost choices), and since it's irrelevant to whether people should be driving (if they're dangerous, get them off the road, period). The second problem is easily solved if we simply make drivers themselves pay for however much it costs to retest them if they want to keep their license, instead of subsidizing it from tax dollars. I think everyone should be retested every 5 years or so, and it should be a challenging driving skills test (the current tests are not).