It is a sad fact of life that for most of us in the UK Heathrow and to a lesser degree Gatwick are the airports from which most long haul flights depart.
To get to the departure gate usually takes hours from the point of departure via maybe a couple of hours trying to check in.
The nightmare of the M25 is part of the process.
Is it not time for a more strategic approach to long haul flying to avoid the funnelling of passenger to a choke point. I wonder how many London departing passengers live outside the S.East.
I tend to use regional airports such as Norwich to connect to Schipol en-route to the Far East and Oz. Ten minute check in with no queues and baggage checked to destination.