"Chetoph" wrote in message
m...
As Crossrail is in all likelihood going to be a regional link, as
opposed to an intercity one, are there any reasons why it could not
run double deck trains similar to those is Paris?

Simple one. Gauge. Crossrail is *not* an entirely new railway, nor is it
proposed to operate on dedicated tracks. At the extremities it will be using
existing Network Rail lines, with all the problems of bridge heights,
trackbed widths etc.

If Crossrail was an entirely new construction, using dedicated track, then
your suggestion would make good sense.