We all know that elderly people are not the sole reason for why are roads are unsafe. However, they are a factor regardless and there should be some sort of system put in place to seperate the elderly drivers that are a hazard to the roads from the elderly drivers that are not.
I know from personal experience that 8 out of 10 times that i've ever been cut off, ran off the road, seen someone run a light or stop sign, etc. it was an elderly driver.
So while many things need to change to avoid accidents as a whole, we are talking about elderly drivers here. And like a few others have already said; having a drivers license is a privilege not a right.