I realise this is about as low as bug priorities get but I thought I'd mention it anyway. The underpass at the southern end of the station on platforms 10/11 cannot be accessed via the right escalator (when facing south) and you can actually see some grass texture clipping through the right side as well. At the north most underpass you can go down the stairs of the same platform but if you turn left (keeping to the right) you can get to the end of the corridor and see where the passengers disappear and a dead end wall. This is blocked if you keep to the left and on the other end of the underpass, so I presume we're not supposed to see it.
Screenshots as requested...the red X marks an invisible wall, circle generally marks where you can walk and where a bit of grass exists.
