Many years ago, I drove from Central NJ to Daytona Beach with 2 co-workers, and then back to NJ again about one week later. Because this was prior to the completion of I-95, it was a longer and more-time consuming trip than it would be today. IIRC, the distance was ~1,100 miles.
On the way South, we stopped-over for one night, but because we really needed to “make time” on the way home, we drove non-stop–except for buying gas & food. In total, the return trip took 21 hours.
With 3 drivers, we thought that by each driving for about 6 hours while the other two dozed, we could do it with a fair degree of safety. On the way home, while I was dozing in the passenger seat, I was suddenly awakened by the lurching of the car and by a lot of noise. As I roused myself, I asked the driver what had happened, and his response was…
We drifted off the road onto the gravel shoulder, but that woke me up!
After that close call, all 3 of us were wide-awake for the remaining 4 hours of that trip.