RW20
Pavement loading considerations take in many factors. The Boeing 757 has a 4-wheel bogey to help weight distribution whereas the A320 family/B737 family tend to have 2-wheel bogeys. A 4-wheel bogey has been seen on the A320 but only as a special modification e.g Air India operating into some airfields. Another example is the Airbus300 fitment of what was called the "La Guardia bogey" ...six Eastern Airways A300's were fitted with wider bogeys to accommodate taxiway weight distribution restrictions.
If I was an airline operator I would be looking at a number of features such as the LDA [landing distance available] on RW20 of 1605 metres after a 3.1 degree ILS approach.......the proposed extension will not affect that. The approach light system is a little "quaint". There is no CAT2/CAT3 low visibility operation. There is history of a jet airliner over-running the end of RW20.
I've flown in/out of Southampton many times, my family and I love the place for its regional airport-sized efficiency and rapid transit [except the Mickey Mouse comical scenes of keeping arriving domestic and foreign passengers separate using tapes and Hi-Viz jacket marshalls to stop intermixing/crossing paths on the way to the arrivals hall] I don't care what the decision is really.....I just want some planes back so that I can fly again.
P.S. Some of you may remember the Air Berlin flights...gosh!!...that motorway looks awful close!! Loved the Dash 8's .......kapow!!!...landed.....aircraft carrier style retardation. I miss FLYBE so much. Regards to all