I was simply making the point that passengers from Southport/Wigan would only wish to travel via or change trains at Manchester Piccadilly for destinations within the southern half of Greater Manchester, East Cheshire, North Derbyshire, Sheffield and some places reached via Sheffield. For some of these destinations, including the Airport, an easy interchange would be possible at Salford Crescent. Thus the effect of not having a direct service from Southport/Wigan via the Castlefield line is limited. The benefits of a more robust and simpler service pattern on the reliability of rail services through central Manchester outweighs any disadvantage of routeing all Southport/Wigan services to/via Manchester Victoria.
Your comments about travelling north from Southport are outwith the scope of this thread. There is a frequent direct express bus service from Southport to Preston and I am not aware of any proposals to re-open the long-closed railway line between these points. Alternatively, passengers can change at Wigan between the adjacent stations.
When services have come from the Bolton direction, it is a much better proposition to change at Bolton than at Salford Crescent due to the ambiance of the station, additional facilities and space to wait. I don’t see how 1tph from Southport is enough to completely decimate reliability through Castlefield, when it can seemingly cope with the same number of services as long as one of them does not originate from Southport.
One of the main reasons Southport will not stand for it’s provision to travel east via Manchester Piccadilly to be downgraded in any way, shape or form is because the provision to travel north to Preston by both road and rail is so poor. Both rail routes to Preston, via Crossens and via Burscough were lost, the M59 motorway, like virtually all investment for Southport failed to materialise and now they want to take away direct services to Manchester Piccadilly! Not a chance.
Southport people may want direct Piccadilly services (or, rather, a rather angry and possibly unrepresentative number of rather vocal people from the Southport line may demand this as their birthright), but there's clearly not capacity through Castlefield for everywhere to have a direct Piccadilly service
For example why is Southport so much more important than Blackburn/ Burnley?
Is it "illogical" that East Lancashire has no Piccadilly service, or is it fine for them to have to change, but the precious people of Southport must have one?
Do Windermere and Barrow justify direct Piccadilly services, or are you relaxed about such passengers having to change to get to Rose Hill Marple, Macclesfield, Glossop, Buxton and Sheffield?
Southport deserves a direct service to Castlefield and Manchester Airport on the basis that it’s the 13th largest town in the north west (and that the service also passes through the larger ones of Wigan and Bolton).
I may live in Southport but I would argue that out of anywhere else, only Rochdale and Blackburn are more deserving of a Castlefield service and Burnley is almost as important. The Blackburn - Manchester Victoria via Todmorden service should be extended around the Ordsall Chord to provide Blackburn, Burnley and Rochdale with a Castlefield service and then run on to the airport. There also may be some basis for the Clitheroe service to serve Piccadilly, but Bolton still requires a service to Victoria.
It is very much illogical that East Lancashire has no direct service to Castlefield or Manchester Airport, but even more illogical that it has no direct service to Southport, Ormskirk, Liverpool, Skipton, Hellifield, Barrow, Hawes or Carlisle.
People from Rose Hill Marple, Macclesfield, Glossop, Buxton and Sheffield are more likely to want to get to Windermere or Barrow than the other way round, but how many times do you want them to have to change? Would 4 be enough?
I can't be bothered with the rest of it as we've been over it many times already, but you miss the point here. I said that connections at Bolton/Salford Crescent with both Southports to Vic would be acceptable if the connections were planned, maintained and of high quality, i.e. no lengthy standing in the cold. That's where I was going with the Nordwesttakt idea. I can just see the connections involving long waits because they won't be planned to work.
But also regardless of Nordwesttakt, changing stations at Wigan will always involve getting completely soaked crossing the road in heavy rain. Some sort of covered passageway under/over the road would be useful.
Windermere is probably the most justifying of a Manchester Airport service compared with anything else in the area other than Manchester itself given its tourist nature. Barrow could easily be lopped back to Lancaster or Preston, ideally again with a planned, timed connection into the Windermere EMU, without annoying too many people.
Rather than cutting Barrow back to Preston, I’d be more of the mind to extend the Morecambe service down to Manchester. If there is no capacity on the WCML, route it or some Barrow services via Hellifield and Bolton.
Covid has demonstrated that, in effect, nothing is established.
Transport Planning is often choosing to prioritise new growing connections and flows over "traditional" ones, to get the collective best use out of, effectively, nationally-funded infrastructure. Southport offers very little potential for real growth, given its largley rural hinterland.
Southport itself is not rural. Is there no rural hinterland around Manchester or anywhere else in the north? Any growth for Southport will be created with the provision of direct services to Preston, Ormskirk and Aintree, as long as they are suitably advertised at each end.
Road building/widening projects often see the concept of “induced demand” whereby providing new infrastructure induces people to use it. If the Burscough Curves, or 4 tracks through Castlefield are provided, then people will use them, established travel patterns or not.