"Tom Anderson" wrote

AIUI, there won't be a huge amount of track-sharing. Crossrail gets
exclusive use of the slow tracks on the GWML, although it'll share with
HEx from Airport Junction to Heathrow Central.

AIUI Crossrail won't have exclusive use of the Relief Lines - freight and,
if Crossrail terminates at Maidenhead, a Paddington - (intermediate stops) -
Maidenhead - Twyford - Reading service will continue, though Crossrail will
be able to dictate the paths other operators may use. Provision of a
diveunder at Acton (for freight joining from Acton Wells or Acton Yard) is
indicative that freight will continue to use teh Relief Lines.

Peter