I know they arent free. but one of the things i carry in my bus is a current or 1 year old Large format Rand mcnally Motor carrier road atlas.. the motor carrier edition has laminated pages, and shows load limits, elevations, hazards, etc that truckers need to heed..
GPS is convenient. but with a bus (esp my slower bus) taking the less travelled roads is fun to do.. it is a royal pain to get a GPS to route you along a route you want to take and at a speed you want to travel.. nothing beats a physical map.. I like the laminated pages because I can mark with dry erase pens and then erase them later.
the book is 11x17 so its fun to lay it out and look for places to drive.
with Covid, many rest stops have closed their visitor information centers except for the restrooms so its a little harder to get maps now.