Gas station maps are the worst in the world. Their folds seem to be cast in iron. My expert navigator just folds them so that the area we are currently in, plus as much of our destination as possible, are showing in an area of map approx 12" in diameter. Trouble with this is that in no time at all folds, both factory and self made, begin to thin out, then tear. So then we buy another map...
Truck stop used to have large, laminated, spiral bound maps that were great. Even included information RV'ers need like clearance and narrow turns. Last time I looked for one was 1992 though. Don't know if they still exist with GPS and all that.
Topo maps and county land maps I cut into 11x17 inch pages and code to the corresponding pages for continuing beyond the current page. Then I bind with individual rings so I can replace pages. (and fix the ones I get out of order to start)