Standard Jet
In reply to your query about runway extension, I read somewhere locally that is not thought likely until the annual pax throughput reaches around 8 million. I don't really understand the significance of this because extra runway surely equates to more routes not currently achieveable rather than extra pax.
I agree that any runway extension would have to be at the eastern end and would straddle the A 38. As this road was diverted a few years ago I suppose the ancient idea of a cut and cover tunnel under the runway would be used. Probably 300-400 metres of extra runway is about the most that could be wrung out, as you say.
There are NIMBYs in the local villages, most of whom have moved into the expanding villages in the past twenty or thirty years (still regarded as 'new people' by many of the old village families). The real locals in the main like and support the airport because it brings work and interest. I grew up in and around Wrington Vale villages in the 1940s and 1950s and still have a lot of contacts with the old village families.
If you listen to some of the NIMBYs you would think something akin to LHR was being planned.
I think a terminal expansion is the most likely next step. I understand it was built so it could be extended relatively easily.
As an airport Bristol is very lucky to serve a catchment area with a large Hi Tech, Aerospace, financial and insurance industry base. It also has an above average number of socio eonomic groups A B and C1 in its catchment area who have disposable money to spend onl eisure, including flights.