More than mere maps, roadlogs are mile-by-mile guidebooks from your starting point to your destination. I started writing them for Sanborn's in the 1980's and now research and develop them on my own. Sanborn's has gotten out of the roadlog business because they were just too expensive to produce. I do them pretty much as a labor of love, though I make enough from them to pay expenses in a good year.
The only thing similar is the guidebook, The Milepost.
In today's electronic world people think they can rely on their phones for directions. That is partly true. But phones generally don't have, "Turn left just past the prison for old mining town where movies including "The Old Gringo" were shot. Keep straight if the high altitude (8,950 feet) would bother you."
Do you need one? No. Will a roadlog make your trip more enjoyable and safer? Absolutely. Even if you are one of those who is adamant about not wanting to spend time on side trips, my roadlogs will tell you if you have a choice of staying in a pet-friendly ex-hacienda or a dumpy motel.
Time and distance are accurately portrayed.
If you hire me to plan a trip for you, I will custom-make a roadlog for you.
The average roadlog runs from 30 pages to 95 pages (Yucatan from Laredo). It is in PDF format and readable on a tablet and sort of on a phone.
Click the link for my store to peruse them.