[aigel]

I always stay caffeinated well, which helps to stay alert. That said, I would not drive more than 10 hours and I would plan two naps of 30 minutes about half way and 3/4 of the way.

I would refrain from stringent (cardio) exercise the day of your drive and the day before. My worst driving trips are usually coming back from grueling hunts or hikes. Then I am physically tired and have to pull over for naps ever 3 hours!

G