In message , at
06:59:25 on Sun, 15 Sep 2013, Offramp remarked:
If only a couple of people are walking up the left-hand side then the escalator can only be working at 50% capacity.

Only if there's a queue to board.

At busy times escalators would be more efficient if standing on both sides were compulsory.

No, walking up both sides would be the most efficient. But the
compromise is that people stand on one side, and walk up the other side.

The tourists are right.

No, they are always wrong.
--
Roland Perry