Pax Britannia's post is exactly whyUK ATC will never manage to change any flight paths.
The routes have been moved to be more efficient for ATC reasons, the residents on the ground complain of noise. Don't forget these are the residents who bought/moved to a house near a major international airport, therefore they should expect noise, or the airport wanting to move routes.
I for one have no sympathy, however the airport authorities listen to NIMBYS, and thus trials are cancelled, efficiently lost.
IMHO, this is the same as buying a house by a river and then complaining if you get flooded!!!!