Eventually, I learned the trick of writing in for route requests, tailoring the request around what maps I'd receive. For instance, if I wanted a Texaco map of Texas, I knew that I could write to the Texaco Touring Service and ask for a trip to a very small town in Texas. If I named a big town, I wouldn't always get the detailed map of the destination, but naming a small town almost always worked.
Sometimes, my requests were for real trips. I vividly remember being the official navigator for the 3-week family camping trip in a station wagon in 1955. That trip took us from New Jersey to Oregon --- at a time when the Pennsylvania Turnpike didn't reach all the way to Ohio!
I was also the navigator on our 1957 trip to Michigan, our 1959 trip to the Smokies, and was both navigator and relief driver on our 1961 trip to Alaska. Before each of these real trips, I'd write to every touring service, and then compare the routes, taking the best information from each.