In message . 145,
Tristán White writes

I must say though that the courtesy between DLR trains at Poplar
(people going from Canary Wharf to Beckton and changing at Poplar) is
still alive and well and trains indeed wait. But no such courtesy
between District and Central any more.

That's because the system is drive by computer and the train is
generally held until the connecting one arrives. Nothing really to do
with being polite.
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