He also sounds angry, selfish, impatient, controlling and unkind. So there’s that.
I get it, OP, and it’s unbelievably tricky to navigate, so I’m here for tips to be honest. My dad is 84, physically fit, mentally switched on, fiercely independent, self-sufficient (my mum died 6 yrs ago), opinionated, drives too fast and drinks too much. (Although he’s very considerate of his partner and would never treat her in the bullish way your dad appears to treat your poor mum.)
I have literally just got home after a white-knuckle hour in the passenger seat of his car in torrential rain, with terrible visibility and his foot constantly on the gas like a lead boot, feeling at any minute as though the last thing I may see in this world is the arse end of a transit van barrelling into my face at 85mph.
Whilst I would hate to knock his confidence or try to curtail his life in any way, there is no doubt that he overestimates his abilities and reaction times to a frightening degree, which ultimately endangers other people. Especially when he insists on driving after a few glasses of wine.
But when and how to tackle this so the conversation lands right is incredibly hard to judge. By implying their capabilities are waning in any way is very confronting (for men much more so than women, I think), and a reminder of their own impending frailty and mortality. People like this are running so hard to escape the inevitable - which is precisely what makes them ‘good for their age’ - that it’s almost impossible to broach these things without running into a wall of angry defensiveness and denial.
My tactic currently is to encourage him to use public transport for long journeys instead of driving, on the basis that he’ll arrive fresher and with more energy to enjoy himself. But I do need to have the speeding and drink driving talks very soon, as I’m afraid he’s going to end up killing himself - or, worse, someone else.