"StaticFish" wrote in message
ups.com...
Question: Why do Piccadilly line trains always stop for around 5
minutes at Hyde Park Corner?

The starting signal on the eastbound can be set to either hold trains to
their correct time of departure, or (more commonly) to clear only when
trains are evenly spaced.

A similar signal exists at Finsbury Park westbound, and I think the starting
signal at King's Cross westbound also as time control, though rarely used
IME.