Correct, however a driver with more skill also has more capacity for driving longer. I don’t think 250 miles (the original point of this whole thread) is long. 750 miles on the other hand… is. I could easily drive 750 miles with no problem. Get to my location, party for several hours and then finally sleep. I know this because I do it about once a year with family. Most people might not be able to go that long. Because they’re not a “skilled driver.” They haven’t built up capacity to understand. Even friends and family of mine when they drive aren’t doing the same things I’m doing. Listening to the car, hearing the inputs and feeling the inputs, monitoring grip levels, ensuring adequate room between other vehicles to ensure accidents can’t happen due to proximity. There’s ways to also lessen mental exhaustion as I mentioned. My car keeping me in the lane and keeping speed automatically for me. Camera systems to watch out for people and other cars with collision avoidance, not to mention another passenger as a set of eyes. A skilled driver would also know where there limit is. I found mine to be around mile 850~ I know this because as I was driving across country rushing back home at night that I didn’t feel I was performing at the level I needed to in order to safely operate a vehicle. No one else on the road for miles, but I switched drivers with my wife who I made nap as I knew I couldn’t do the whole 1000 miles needed in one go. That’s also the difference in skill. Knowing you’ll need assistance and making sure it’s in place when you do. Like having a hotel booked at 700 miles (or whatever mile marker a driver can safely drive) or making other stops as needed.

I’d be interested to see a study on it, but I’d wager that Americans and Canadians can drive for longer than their European/Asian counterparts. Just due to the “training” we have of driving longer distances more frequently.