Silver,
There the case for doing SOMETHING was made as watertight as possible - listing all the important destinations in South Ameica and China that LHR cannot service because of capacity constraints (and noting that both CDG and AMS do service these destinations
For a long while, I remained pessimistic about the future of UK aviation. Think of the serious challenges - rising fuel costs, global warming (I know you don't believe in it, but most people do, and so does the government), and the clobbering from APD.
However, there are the plus sides too - namely people living longer and having more leisure time. That is where the 400m pax per year comes from, not from China - although I still think that is way to optimistic.
Recently, there has been an up-surge in routes from Asia, in particular recent routes announced to LGW from ICN, HKG and PEK, joining last year's new routes from HAN & SGN.
Throw these together, and I think London could do with another runway - but four would be overkill imho.
None of us have crystal balls, but the government doesn't have cash either, so airport development has to have a solid business case. Decisions will therefore, for better or worse, be taken by accountants, and they will be conservative.
Also, LHR can serve whatever routes the airlines using it want to - but in order to add a destination, somewhere else needs to be cancelled, or moved to another airport. As we are seeing, this doesn't always mean AMS / CDG etc, sometimes it is just LGW!
They also had quotes indicating that Chinese tourism and trade is being diverted away from London, because of the poor state of LHR (queues, gridlock etc).
They are also investing £1bn in the new 'T2' - which apparently is the same size as T5, but less than 1/4 of the cost - WITH inflation! Wish I could say the same about costs of HS2 re: HS1!
(or is there a lot less ground work / airbridges / rail tunnels etc on this project - could anyone enlighten me?)
T5 gave LHR a lot more space, but pax numbers remained the same - I assume this is due to runway usage restrictions, and that the same applies to the T2 / central complex. Was this planned in anticipation of R3 and then built anyway?
Either way, under the current arrangement, LHR should end up with the same no of pax using a lot more space - better for the Chinese that can get in, better for everyone else too.
Not sure where we got to re: mixed use of LHR runways?
And as for other tourists using other European hubs, do the maths. You are spending a fortnight driving around Europe - do you get stung by UK APD and pick up a right hand drive car, or do you fly into CDG?
It isn't
all about capacity!