"no recollection" is a bit of an overstatement, it's more like how you described with parts of the highway missing from your memory."With no recollection"? Well, I don't remember some parts of highway I've driven, sure. But I don't feel "hypnotized", mainly because I just crank up the music, and sing along.
I also once did a roadtrip, and listened to some audiobooks. It's a great way to spend time on the highway.