On Wed, 3 Oct 2007, thoss wrote:

One of their advantages is said to be that, with all doors being used
for both entry and exit, they are quicker to load. Couldn't this be
done also with double-deckers?

You've still got the stairs in a double-decker, though, so you just move
the bottleneck.

tom

--
Never attribute to malice that which can be adequately explained by
stupidity -- Hanlon's Razor