I have maps from the late 60s and early 70s. I think just as fascinating as the "what's missing" are the routes marked "under construction" and whether they were ever completed. I remember riding the Baltimore Beltway, and they had signs with distances to exits, and the ones that didn't exist were marked "FUTURE". As an 8 year old, I would belly laugh at the thought of being able to take an exit that would lead us to the future. The one marked "FUTURE" eventually became I-795.
I still prefer reading a map to using a GPS. As a kid, I used to love unfolding maps on my floor and looking at them. I can still look at Google Maps on my computer all day...but I pick my routes. In the police department where I volunteer, our Key Maps hadn't been updated to include a highway that opened in 2014, so when our patrol cars with GPS transponders drove on the highway, it looked like they were going 4-wheeling (they've since updated the Key Map, but it was fun to watch the cars driving over supposedly "green" spaces)