So with the new leaked screenshots we have also seen a part of the map. It does appear that Vault 111 is in the northwestern corner, with Sanctuary Hills basically just down from there. Further down we see the Red Rocket gas station, likely where you meet Dogmeat, and this is where the screenshots are taken.
So I wonder what this can tell us about the possible size of the Boston wasteland. What we see in the pipboy is obviously a zoomed in part of the map. So we have a scale on the left and on the top of the map. The first thing we can roughly figure out how long one of these bars actually is. Considering another screen with a questmarker and distance to Sanctuary Hills of 80m (or yards) from the fence to the centre of the settlement. I guess there might be 40m more to the top and Vault 111 entrance. Therefore I guess after judging the distance between the Vault and Sanctary Hills to be somewhere around 120m that in the pipboy map the scale seems to be a 100m for each bar.
This translates to, in this screenshot, and this zoom to 1,6km x 1,2km spread.
Further along the road, probably around 200m there is the Red Rocket gas station, where you fight the molerats, we've seen from the E3 trailer. Then another 200m further we see a door(?) pointing to the next questmarker, presumable the main story. On the map and radar it is on the same spot as a town. This leads me to believe this is Concord, where you meet Preston Garvey. When we arrive there we already crossed a third of the map section, but only got to stage two in the main quest line.
So let the assmuptions begin...I personally think the map section could be anywhere between 1/4 and 1/16 of the whole map. What do you guys think? Is there anything else we can assume from these screenshots in terms of size and location density? Have you noticed anything else in terms of possible locations and landmarks? I've only seen this Watertower or what it is further down in direction of Concord. Is there anything I missed? Could one make out something in terms of scale of the local map or similar?