"Mizter T" wrote

However the best way to approach it from south London is surely by
train or tube, though not at rush hour! The London Overground WLL
service will take you up there from Clapham Junction, and come
December (unless I've got this muddled) trains going up the WLL from
will be starting from East Croydon stopping at all stations via
Norbury and Balham (I forget - is this service going to become more
frequent than hourly?).

Another alternative of course is simply not to go to Westfield, and
instead to go elsewhere - south of the river Croydon, Bromley and
Kingston instantly spring to mind as large shopping destinations.

Though South-east London doesn't have any one-change train journey to
Westfield. They can however drive (or get a bus) to Bluewater.

If you go by train to Greenhithe for Bluewater (nice new modular station)
with a through ticket to Bluewater you transfer on Fastrack Route A. This
has a bizarre [1] system whereby you must obtain a ticket from the bus stop
ticket machine before boarding. Even if you have a through (rail issued)
ticket you have to use the bus stop ticket machine to obtain a zero fare bus
ticket. On Friday three teenage girls didn't understand this, but, excellent
service, the bus driver got out and showed them how to do it.

[1] At least if you have a (physical) travelcard, or a Freedom Pass (or
indeed a concessionary travel pass issued by a local authority anywhere in
England) you don't need to obtain a bus ticket before boarding a central
London Bendybus.

Peter