I know plenty of folks who could study a map for days on end and still have no idea what was on it. I'm the opposite, I remember the layout quite easily, and am fully capable of relating the map image to actual roads.
When the girls and I went to Chicago I had no idea how bad they were with directions. I had looked at the city on Google Earth before we went. Found our hotel, House of Blues, Hard Rock Cafe, and the major tourist attractions. I just "toured" around, looking at street names, bridges, the river, etc. On our first day we went out walking. I wasn't leading at all, the one girl had been there before and took the lead. When we headed back towards the hotel to go for dinner I wasn't paying attention to where we were going, I was just enjoying the sights. Then all of a sudden the girls stopped and looked around. They had no idea where they were or how to get back to the hotel. No one had a map, and they didn't even know the street name that the hotel was on. I looked around, saw the sign for House of Blues across the river, and knew exactly where we were and how to get back to the hotel. They were pretty amazed that I knew that without even having a map. But I had the map in my head.
I grabbed a map at the hotel to carry with me the rest of the time, but for the most part I didn't need it. I'd look at where we were going, and that's all I needed. The other girls typically didn't know which way to turn when the walked out a door.
If I road trip with my niece and nephew, I hand them the map book and tell them to navigate. Elizabeth (7) struggles to keep up with our movements. She easily loses her place on the map and by the time she's found the road name, we're far past it. Austin (10) can not only keep up, but plan ahead and tell me what roads are coming up next. And which way to turn. He plots the course, usually taking the route with the most bridges possible, and I follow it.