On Mar 20, 12:40 am, "Peter Corser"
wrote:
The trains you are thinking of are common in Europe, USA, Canada, China (I
think), at least.

They are, however, only double deckers in practice. The middle levels are
only over the wheels and are usually used for entrance/exit and standing
customers only (there may be tip up emergency seats in some instances),
there is still only room for two sets of seated passengers even within other
countries extended loading gauges.

Normally in Europe I think the doors are on the lower level - the
space above the wheels is seating and a sort of landing halfway up the
stairs.