Seniors And Walkable Neighborhoods

I occasionally read that seniors are likely to be a strong constituency for walkable, public-transit oriented neighborhoods.  This argument runs as follows: seniors gradually lose the ability to drive as they get older.  Thus, they are eventually going to need more transit and more walkable neighborhoods, and designers of walkable neighborhoods should be especially focused on the needs of seniors. 

But after spending the last few weeks with my parents and (occasionally) their eightysomething friends and acquaintances, I notice that most of them can drive (unless they are disabled with Alzheimer's or another major disease)- and the ones who can't drive often can't walk much either. In fact, a major area of conversation among seniors I know and their children seems to be the dangers of walking- not danger from cars, but danger inside the house from falls, leading to broken hips and knees.   (In 2011, more than three times as many seniors died from falls as from motor vehicle accidents).  

So it seems to me at least possible, based on this highly anecdotal evidence, that seniors' ability to get around without driving may degrade over time- and may even degrade more rapidly than their ability to drive. 

Having said that, I don't really have any data on this issue, and I can't pretend to have met a representative sample of American seniors.  It seems to me that there are really a few questions that might be worth knowing the answer to:

1.  How many seniors can't drive? (One website says 20 percent).

2.  How many seniors in category (1) owned cars and could drive at the age of 60, as opposed to being perpetually unable to drive due to low income or disability? 

3.  How many seniors in category (2) can walk enough to use public transit and otherwise get around on their own in a walkable neighborhood?