If you have the time, could you explain this? I loved the ADC maps and have a cartonfull of them in the trunk for much of the mid-Atlantic region.
They were a local co (Alexandria Drafting Co.) which did its own original work in our region (at least, starting in our region).
Since they were bought by German language/map behemoth Langenscheidt, they changed. They’re still excellent, but sometimes more out of date than they used to be. I hear they’re owned by another co., now.
I learned about them when my mother was in Real Estate - huge thing. They were still local. We always had some of the most local maps on hand. I started relying on them heavily just for my local forays looking for graveyards, etc, just exploring the back roads.
After Langenscheidt I noticed some errors, sometimes just things that weren’t updated for new traffic patterns.
Regardless, I love the things and as a birthday present, my husband bought all ADC maps for Maryland, so we had them all on hand and all were consistent with each other, at least!