What you’re describing is land lock. Now, Stefen Molleneaux (sp) answered this question using his DRO theory:
see: But – what about the roads?
However, Most property owners would (I believe) attempt at developing some contract with their neighbors in who they can and cannot sell their land to. If it was the case that people were getting land locked by big road companies or what have you, I think you’d see neighborhoods develope in a way where land lock was neigh impossible.
And if some road company is being a giant phallic appendaged to a bunch of homeowners, I’m not so sure people would be inclined to use their roads.