That's the trouble isn't it Bill? Having to assess in a split second the sudden dangers that present themselves. One needs instant reactions and constant vigilance. That's why I firmly believe that elderly folk should be assessed regularly for their capability to react swiftly when driving.
I'd be quite happy to undergo such a test, and to accept the findings. If it was felt I should surrender my licence, I would do so with good grace.

Every time we exit our village and enter the main road, we pass a very sad little wooden cross nailed to a tree, where a young motorcyclist met his death. A motorist pulled out without looking, his bike wasn't seen approaching and the resulting crash was horrific. His poor family put the cross there and lay flowers at the scene every year.