There is still bad congestion at the bottom of the picc/northern
escalators for example, where flows cross each other.

Yes, I'd forgotten about that one at KX too. I guess so much of it is
historic and would cost a fortune to put right now. A lot of the newer
stations are better in this respect although not perfect. The design of the
sub surface hall at KX has got most of it right, with separation between
the barriers and platforms and one way systems, it's just everyone ignores
them.

D