Rich and Strange Aeons

Aha, thank you to you and squirrelitude for explaining. And, yeah, Greater Boston's old and dense enough that I guess it ends up rather more integrated than some other places I've seen. E.g., the last couple of places I lived in Scottish villages, driving past my house just does not get one to anywhere far away on the other side in any sensible way because there is no good connection at all. Even in central Ohio, a fair few large housing developments had an entry from larger roads on one side but no useful way out from the other side, so the topology wasn't tempting in the first place, probably not where I am now either, though that might partly be because the state route one might want to connect with is on the other side of a stream.