"Basil Jet" wrote

http://content.tfl.gov.uk/station-design-idiom-2.pdf

I haven't read the whole thing, but I'm laughing already.

"Oxford Circus Underground station directly connected to diagonal
crossing above" - since the station has an entrance on all four corners,
the existence of the crossing has no relevance for the station.


The existence of the diagonal crossing on the surface made a great deal of
difference when some of the 'entrances' were exit only and some entrance
only.

"Have you sealed off all the exits to prevent the robbers escaping ?"
"Yes, but they may have left by an entrance."

--
Mike D