I wouldn't expect TfL to allow the buses to run over a parallel route to the trams, even non-stop. The pro-bus retention argument was lost, to all intents, when the trams were introduced in 2000. I still believe the 54 should not have been withdrawn between Elmers End and West Croydon.
Tramlink is ridiculously unreliable at the moment, and of the 8 running cards on the Addington route, there are regularly only 6 trams in service, and there is no hint as to when the tram availability issue will ease. They should just introduce a six-tram emergency timetable on this route (10-minute headway vice 7.5) but the current situation is so silly three trams come within 15 minutes then the next one is another 15 minutes away. Sometimes they do delay the previous one before the 15-minute gap slightly and bring the next one forward slightly to run a roughly 10-minute even headway, but that is not guaranteed. In any case the tram is actually regularly slower than 466 on this stretch off-peak.
I wondered, since the start of the announcement for the project, whether the "X119" should duplicate capacity via West Wickham, as the demand may not be there for an additional 4-5 bph.
Running it via Addington Interchange does however allow a comprehensive review of routes in the area. I would imagine that routing could allow 466 to be curtailed at East Croydon or Shirley (poss -3/4 PVR), or more daringly Katherine Street (maybe -6 PVR) and possibly 353 at Hayes or, if demand requires due to possible reduction on the regular 119, diverted to West Wickham (-1 PVR).
Shirley to Addington Interchange does not see a huge number of passengers boarding/alighting en route, so "X119" can serve all stops without impacting on the running time too much. Even if it needs to run limited stop to be consistent with the rest of the network, 5bph on the existing 130 should be more than sufficient. The busier school runs can probably be catered for by the 1-2 bus daily extension on the 466/double-run/diversion of 198.
Forestdale can then be replaced with a double-run on the 359 which is a reduction from 8bph to 7bph overall (including 433) and I think 359 can possibly do that without any additional vehicle requirement off-peak, although that does mean Monks Hill will suffer longer journey times in the Addington direction. Saying that some can feasibly walk to the main road and use the 64.
314 can be curtailed at Addington Interchange to help improve its shocking reliability and offer potentially 2-veh saving. 464 can be extended via Gascoigne Road following existing 314 routing terminating at Addington Interchange. Alternatively 464 can do that and be extended to Forestdale instead of 359 (both are 2bph), or even merging the two routes together.
Gascoigne Road as a result goes from 5bph to 2bph, so divert either 2bph or 3bph on the 64 that way. I know TfL don't like running buses on the same route over different roads but the middle section of New Addington via King Henry's Drive doesn't have the demand to justify 6bph on 64, and in any case are short walks away from Tramlink/130.
That to me covers pretty much everything and offers a decent PVR saving.
The biggest problem with running the "X119" via Kent Gate Way is the congestion westbound approaching the Addington roundabout, which is a big headache for existing bus routes.
Personally I think the renumbering of the 607 and X68 ridiculous, even more so that it’s ridiculous that these routes are part of the Superloop, they should be part of a separate network of radial express routes that parallel the stopping service.
I do wonder with traditional bus people from the LT empire no longer at the helm, whether respect for some historic LT practice is gradually being eroded.
SL just reminds me of Station Link (who still remembers those?), so I would think if they really wanted a network name along those lines something like SP (for SuPer or SuperlooP) must have been better. They can then as some suggested go clockwise around the loop increasing in number (X140 >> SP0, "X183" >> SP1, "X34" >> SP2, ..., "X119" >> SP5, X26 >> SP6) following the LT convention where at least last digit(s) match existing routes. 607 can even be SP7, X68 be SP8, and the proposed X239 >> SP9, neat, not that I am a fan of including these in the network.
But just wasting money updating the route numbers (hence smart blinds and all publicity) without any associated changes like they are seemingly doing now with the 607? Can Khan pay for it out of his own pocket rather than waste taxpayers'?