Dartford became part of the Oyster recently and the housing market is on the boom in the area; especially with the mass house building that's going on. Commuter wise I don't think the Dartford - Bexleyheath etc is important because people tend to commute into London rather than commute locally. But the problem then becomes how much are you shifting those commuters in Dartford onto the other two lines. Creating more of an issue than it solves. However my point is more of the locals. Removal of any option from Dartford to all stations along the Bexleyheath would be bad. Forcing a change at Slade Green I think would create more of a problem. You will need to re-time the service so that there isn't a wait. It will push more services round the loop and I think it would create a bit of a bottleneck.
I think that maybe looking at the outward parts of town is the wrong approach. Great though it would be to just send everything into Dartford, that's not feasible and realistically, 2tph along local axes (which can be handled by buses), is probably sufficient in many cases. The importance is sorting things out at the London end, where we have lots and lots and lots of flat junctions, with services pretty much going from anywhere to anywhere.
I agree. I think I've posted the same suggestion before. Everything North Kent side goes to Cannon. Everything Mid Kent side goes Vic or Cross. It would be a little draconian because of the Hayes services don't get a Cannon Street service. Vic's will need to move to the Dartford Loop and Orpingtons/Sevenoaks will be affected as where do you send their Cannon Street services ?
I'd certainly hate to be a planner
Well, if we look at current frequencies. We've got 6tph from Bexleyheath and 4tph from Crayford, with 4tph from Orpington and 4tph from Hayes available to present themselves at Lewisham (ie: the complex series of junctions between St John's, Hither Green and Ladywell). We've also got 6tph from Greenwich North of New Cross.
Let's work on the premise that we "don't care" what happens at the Dartford end, (ie: we don't need to specify 4tph along any given axis around there). We also want to achieve 4tph on any given line into London and maximising connectivity (ie: have lots of trains at Lewisham), while minimising flat junction conflicts.
Given where the Greenwich services "show up", they have to go to Cannon Street. Otherwise, they'd have to do complicated cross overs onto the fasts and we don't want to get in the way of those. How much better could Lewisham handle everything coming into the Southbound platforms not crossing over into St John's - ie: all via Tanner's Hill or to Victoria. There'd be a huge temptation to send the whole Hayes service via the avoiding line, but that means stopping 4tph on the fasts at New Cross or forcing everyone express to London Bridge and Charing Cross, which I'd posit wouldn't be good enough from a connectivity standpoint. We still have 8tph turning up at Hither Green as well. Currently, Tanner's Hill flydown handles 6tph, if we can push that up to 8tph (which might be feasible, if we decide to take out the 2tph from Ladywell, that bypass Lewisham), we could run all the Hayes services via Tanners hill and then one of either Orpington/Sevenoaks or Crayford services to Victoria, with the other via Tanner's Hill to Charing Cross. Well, Orpington already has 4tph to Victoria (via Bromley South), so we should run the "SEML Slow" services to Charing Cross and the Crayford services to Victoria (which eliminates an awful lot of flat crossings at Lewisham). It also means everyone who needs to change from Charing Cross services to Victoria services has an easy same-platform interchange at Lewisham. With any Cannon Street passengers able to use London Bridge. The greatest inconvenience comes for St John's and New Cross passengers from areas that aren't North Kent, which have to change platforms at Lewisham.
That leaves the Bexleyheath services, which should all run to Cannon Street, via St John's and New Cross.
I think this works, without horribly disadvantaging anyone.