How much quicker would Princes Risborough - Oxford be via Thame and Cowley be than via Bicester Village?
Depends on how you were comparing it. Considering it was mainly single track with station loops via Thame and nowhere near the 100mph the Chiltern line is. Measuring it on Google Maps, its 33km/21 miles via Thame. Its 40 minutes now with stops at Haddenham, Bicester Village and Oxford Parkway. You would suspect Thame would have a stop, possibly a parkway at Oxford services, probably Wheatley, BMW/Blackbird Leys and the Science parks. A stop normally costs you 1½ minutes, so 7½/8 gone there. So if you assumed 60mph then 30 minutes, so 10 minutes quicker, 75mph 15 minutes quicker. Its all moot though as we have done this one before, too much built on and Chiltern looked at it and walked away.
Maybe heading a bit off-topic now but relating to how things might have been/ might yet be if things were reconsidered with different criteria ...
I have vague recollection of the Chiltern/ Evergreen 3(?) plans/ consultations looking at whether better to reach Oxford via Bicester
or Cowley. I agree with The Planner that the route beyond Cowley is too much built on. I seem to recall (from somewhere/ another thread?) that there had been a service between Oxford and Marylebone (or Paddingon) via Thame, though it might have been with a change at Princes Risbough.
I have a 1938 ABC which indicates Oxford (G.W.) From Paddington via Didcot Ordinary Single 13/3 adult, 8/0 child via Thame 11/8 adult, 7/0 child. The train times listed thereunder do not indicate the related routes* (nor stops, though if I put the time to looking up eg Culham or Didcot or Reading or Thame or Princes Risboro I could possibly work it out!). I note that the first train for London departed Oxford 7.10 (arr 9.00) and the next 8.35dep- 9.50arr.
* One train each way is shown as
v via Beaconsfield Oxfd 11.20dep- Padd 1.40arr; Padd2.25dep- Oxfd4.45 arr
.
That ABC also shows Oxford Another Route (L.M.S.) From Euston, 13/3 adult, 8/0 child [i.e same fare as to Padd via Didcot], first train 7.24dep, 9.53arr.
I imagine these journeys involed a change at Bletchley, but it's not stated, unless I'm missing it!
In passing I note that today it is invariably quicker from Oxford Parkway to London via Oxford; from Bicester (North or Village) to London Marylebone; from Islip depends on time of day, and readiness to change at Oxford. I would imagine that ultimate destination in London will influence choice of route, and/or maybe degree of familiarity with tube connections etc; and best offer of return trains, eg times, frequencies. For me, likelihood of getting a seat is key consideration.
Travel patterns have change hugely up and down over time- commuting, studying, shopping .... I've said it before- praise and sympathy for the planners trying to get it 'right', esp when things take so long (and cost so much) to get from idea to trains running, or plans developed and cancelled.