Can computer modelling be used to improve operational decisions, e.g. whether to hold trains?

[Bletchleyite]

From https://www.railforums.co.uk/thread...s-on-a-large-scale.205879/page-2#post-4642717

You can do that now and have been able to for a good number of years, and it is done on smaller scales but the computational power to do it and the time it takes is still quite onerous as i pointed out earlier. But even then that only spits out numbers on punctuality based on a number of "runs" with historic TRUST delay data put in, it cannot make a decision on its own (yet) on stepping up units, what gets regulated etc. during perturbation, it just tells you what happens and can point you in the direction of what to look at. Then the cycle starts again.

That's something that could potentially provide big benefit in the future. With more and more people purchasing travel via journey planners (and by and large sticking to it even if they don't have to, as what's the point in using a planner if you have no intention whatsoever of using the trains it suggests?) that gives you a huge amount of data to play with in working out who's likely to be making what connections and the likes, and being able to, for example, model the possible effect of holding a connection in deciding if it's best to do that, or even to know in advance you're going to need some taxis (so get the guard on affected trains to go and find out exactly how many are needed, and provide that to the system, which could then automatically order them from a partner taxi company).

If e-tickets are being scanned, you might even be able to use that data to get a better idea if people are making connections or not.

At the moment we mostly don't hold connections as it's too complex to work out the knock-on effect, so the assumption has to be that unless it's a really simple case like one of the Cornish branches where you know you could hold for the length of the turnaround at the terminus minus the end-changing time you don't hold. Modelling could provide the knowledge to make a better decision - which may still be no, but it'll be yes more often than it is now.

 

[The Planner]

Traffic management systems coming into play should help as these (and im sure there are older systems about too) give you a "live" graph. Im not sure they can make the decisions for you but in conjunction with CDAS (which has its own inherent issues in my view) on trains it will mitgate. In your above example you need to agree what the perturbation turnround can be vs the planned one too.

 

[HSTEd]

Hitachi Claim to have this capability.

Supposedly TRANISTA can automatically replan timetables to optimise running in real time.

 

[biko]

This should certainly be possible on a small scale. There are many research papers about holding especially for buses. I recently wrote a paper about the optimisation of holding of buses based on the regularity, waiting times for connecting passengers and waiting times of passengers that were already on the bus. I applied it to the bus network of a city which on a normal laptop took about a minute. So it should be possible with more computing power for a certain region.