My local Underground station is Leyton which is extremely busy. Even
off-peak passengers stream down the steps onto the west-bound platform
at a rate of about ten people per minute. Running at three minute intervals,
each train picks up around thirty passengers.

One Saturday afternoon two years ago I was at Eltham station. Trains were
running at either 20 or 30 minutes intervals: I can't remember now. When my
train arrived, there were about fifteen passengers waiting. I couldn't
believe it!

This point is often over-looked by South Londoners who complain that
London Underground operates mainly north of the river.