Answer their texts, be polite, and enjoy.

Which for me is usually followed by "you're not driving and texting right?" lmao

As a solo traveler, my friends will ask me to check in from time to time. A few years ago I drove from Flaggstaff through Sedona on my way back to Phoenix (my brother and the others went on to the Grand Canyon) - an absolute gorgeous ride that had me think two things 1) would be nice to share the scenery with a friend and 2) still not a bad drive to enjoy solo on my own schedule :) Since I was in AZ, my friends on the east coast didn't know my schedule so there was no checking on how I was doing.