Driving old vs. driving drunk

I came across a Fox News article titled Driver's seat safer than sidewalk for older adults. To quote one researcher cited in the article:

Assessing whether older adults can drive is important, but the problem is it leads to policies which are becoming tighter and tighter and distract us from older adults at risk as pedestrians

The article notes the following:

Researchers found the risk of being killed when traveling on foot was five times higher for older people than for the young.

That brings me to the related question then of whether a similar focus would lead to an increase in drunk driving. To quote Steven Levitt of Freakonomics:

every mile walked drunk ... turns out to be eight times more dangerous than the mile driven drunk.

Five times the risk for old people to walk instead of to drive versus eight times more dangerous to walk drunk versus driving drunk. The real issue seems to me to be the risk to others on the road which the article doesn't really get into.

There may be something to the article's assertion that seniors aren't as risky drivers as portrayed, but I'll leave discussion of that for another day.