Tinmug: you are completely right. But we have to control our population, too.
The trouble is, none of our politicians will ever put population control up for discussion because they think it would be political suicide.
Congestion is not the only problem. All the money we spend in coping with ever increasing demand for everything - roads, hospitals, schools etc etc is keeping us poor. Ask the rail commuters if they enjoy paying more and more for season tickets to fund extra track and carriages.
Sorry about the thread drift, but loss of airfields is only symptomatic of our much bigger problem. The more the problem is given an airing, the sooner it will become generally recognised.