While age can and does make a difference, overall health is the best indicator. We are both 68. DH has not driven our 40' Phaeton since 2009 when he experienced numerous heart events. He has been a heart patient since 1998 when he was 47 years old. But at 59, he hung up his keys to the big motorhome. He still drives the car and our 22' motorhome, but the thought of driving a big rig of 40,000 lbs down the road is not a risk he is willing to take. He is an excellent navigator and keeps me on the right road using his laptop. He also watches the engine stats with his Silverleaf. We make a great team. I love to drive, having learned tips from my trucker Dad. It all works for us.
Dale