If you opt for the cheapest fare then its pretty simple, but if you want to see the options then there are loads of options, I will often check the price differential between some sort of open ticket (typical off peak day return) v Advances, and if the difference is minimal I buy an open ticket 'just in case' A good example of the complexity is Anytime day v 1 month returns. Why not just offer 1 anytime ticket valid for 1 month, at say £21.50.
OK so you are abolishing day returns, but that means a price rise for many people, as the non-day returns are typically more expensive, for anything other than long distance journeys.
York to London would probably have two rates: 1st based on current Super Off peak fares "an Off peak ticket", second would be anytime.
How would you calculate the price, and what would the restrictions be?
Intermediate stops would be pro rata.
That would likely enable splitting opportunities, for journeys that are partially during peak hours, unless you have very complex peak restrictions.
Advances tied to specific trains would still be available, and I would probably introduce dynamic pricing, if the xx.xx departure looks like its going to be almost empty drop the prices, if its looking full and rammed suspend advance sales. I am sure with all the data gathered now, and a bit of common sense human input applied regarding events that affect loading a reasonably effective algorith could be developed.
LNER already do dynamic pricing, but the "almost empty" trains are still expensive.
Would dropping the price after people already booked be a popular move? Would it make things simpler, knowing that leaving it until nearer the time could see a reduced price?
Any changes have to be revenue neuteral, once you have a price for every station to station section, then arriving at at through price which will always be the same as a split ticket is easy.
OK so what are the prices for:
York - Ulleskelf
Ulleskelf-Church Fenton
Church Fenton - Micklefield
Micklefield - East Garforth
East Garforth - Garforth
Garforth - Cross Gates
Cross Gates - Leeds
Church Fenton - Castleford
York - Castleford
Castleford - Woodlesford
Woodlesford - Leeds
Castleford - Leeds
Would York - Leeds be the sum of the former, or the latter, or something else? Would it vary depending on the route the train is booked to take?
The only issue then is routes where you have a commuter and an Inter City service options.A possible solution: Assuming you do away with ToCs wrt to ticketing then some services are labeled as Inter City, which require a supplement over certain sections. To take the case of York to London, Peterborough to London would be one of the segments. If you buy a York London ticket then it includes it. Travel in Germany used this model, I dont know if it still does. If you change your mind then you just buy the supplement.
How would this work for York to Leeds? What is TPE categorised as? How many fare types would you make available? How would supplements be priced and purchased?
This isn't all the answers, and obviously you will have anomalies with will require manual tweaking, but they should be odd ball situations, not the norm. You then decide if you are tieing yourself to specific trains, going for offpeak flexible, or anytime ticket, but split tickets will deliver the same ticket price as a through ticket.
It seems to be more complex than the current system to me?