I have to say, every time I look at the planned branch doing nearly a
right angle at Seven Sisters, I think that some clueless manager saw the
abandoned Palace Gates branch on a map and told their underlings to use
it, but when their underlings pointed out that it was largely built on,
said "I... meant a tunnel... obviously" and they haven't been able to
subsequently admit that they cocked up and they never would have
suggested that alignment at all if they hadn't thought it would be a
cheap line along the surface.