The failure in the past of line closure rail replacement bus services, in my opinion, was that they replicated the railway route and thereby missed out nearby traffic opportunities.
Yep. And that they haven't been integrated into railway systems.
It is very, very easy to travel from London to Keswick by public transport. Euston to Penrith, walk outside, board the X4/X5.
But if you type Keswick into the railway journey planner, there's no station, so they drive.
Ambleside via Windermere is the same. As is Pen y Pass for Snowdon. How many cars could avoid being driven into National Parks without changing the physical service in any way by just integrating fares and information provision?
It's a little ironic that the reason the Bletchley - Bedford section of the Oxford - Cambridge line remains open is because the local bus operator was unable to provide the resources for a replacement service when closure was agreed, not that it was considered that hardship would be caused by the rail closure.
The Marston Vale is actually quite a complicated one, though possibly easier before Milton Keynes existed.
What you would probably need is:
- Fenny Stratford/Bow Brickhill - a matter for Milton Keynes local bus services more than the railway
- Woburn Sands - reasonably frequent bus to Central MK via Kingston as part of the urban MK system (as it had until the planning gain ran out)
- MK-Bedford fast - already provided by the X5
- MK-Bedford slow via A421, Ridgmont, Lidlington, Marston Moretaine, Wootton Broadmead then either Wootton or the B530 (and Wixams once it's finished and has a way through), occasional, timed around schools/office commuter times and Amazon shift changes at Ridgmont
Which notably is totally different to what was needed when Beeching was about!