How would a national regular interval timetable be planned?

[ChiefPlanner]

That's certainly something places with a bitty rail network such as Wales should be doing. It's inexplicable that they actively decided (it's minuted somewhere) not to build Trawscymru into this.

It was suggested and scoped out in general terms as long ago as 1999 ....no action taken.

 

[waverley47]

So let's start with a hypothetical takt style timetable. As mentioned, Switzerland conveniently is a chessboard of 60 minute journey times, but the UK is a bit more complex.

Next, do we do just the intercity network or the full thing? Intercity would be easy, but these things aren't always clear cut. The north ECML for example is also the suburban service; in an ideal world, Berwick and Alnmouth wouldn't be served by the fast IC services from London to Edinburgh, but we make do.

Next, there are problems with pathing. Again, in an ideal world, services would be evenly spaced, but freight paths are important too. Over Beattock, the passenger paths are flighted to make sure that freight trains have as clear a run northbound as possible. This means you can't have even spaces between services, and therefore a perfect timetable where all three trains per hour are 20 minutes apart.

Finally, importing delays. Cross-country services have an awful habit of importing delays from certain parts of the country to others. Seven hours and six hundred miles is probably too long for any service under a takt timetable, but people don't like to change, and cross Birmingham services are important.

In an ideal timetable, path every freight as either 75mph electric or 60mph diesel. Then, cull every service extension, they're too unpredictable; this includes Crosscountry beyond Plymouth and Edinburgh, GWR beyond Swansea ect. Regular service patterns are nice and easy to timetable.

After that, once you have your core backbones of intercity services and long distance freight paths, then it's time for local and suburban. The most successful takt timetable on a reasonably sized and varied network in the UK is probably ScotRail north of Edinburgh and Queen Street. Trains are the same every hour, with no peak extras, and regular calling patterns, with a mix of IC and stopping services. This is because there's little freight, virtually identical train performance, and everything is rather self contained.

Outside of small areas such as this, it's unlikely you'd be able to get everything to work together well enough, without it falling down every time someone sneezes in Birmingham. By definition, it's always going to be easier to timetable a small network than a large one; the UK network is just too big and too complex.

 

[SynthD]

How does peak times fit into this beauty over stability plan? I can follow how it works for weekends, unless there's a sports event on.

 

[43096]

As mentioned, Switzerland conveniently is a chessboard of 60 minute journey times, but the UK is a bit more complex.

It isn't "conveniently", it has been planned like that to lower journey times to under an hour (to allow connections, obviously) with infrastructure improvements such as the Mattstetten–Rothrist NBS to achieve it.

 

[squizzler]

Meanwhile in Britain the Victorians who engineered the original network were meticulous in trying to make interchange between competing company’s lines deliberately inconvenient. An un-takht, if you like.

This means the best way to get a takht railway - and the answer to the question posed by the thread title - is not to start from here! But it does not mean that we should not start reshaping the network to be more takht-like, even with the realisation it will take over a generation to implement.

 

[Bletchleyite]

Meanwhile in Britain the Victorians who engineered the original network were meticulous in trying to make interchange between competing company’s lines deliberately inconvenient. An un-takht, if you like.

This means the best way to get a takht railway - and the answer to the question posed by the thread title - is not to start from here! But it does not mean that we should not start reshaping the network to be more takht-like, even with the realisation it will take over a generation to implement.

Indeed. A start would be to look at what connections people would actually use and enable those where possible - not all of them will be.

 

[Ianno87]

Indeed. A start would be to look at what connections people would actually use and enable those where possible - not all of them will be.

That's already done.

 

[Bletchleyite]

That's already done.

I'm not convinced it's done to an adequate extent.

 

[30907]

How does peak times fit into this beauty over stability plan? I can follow how it works for weekends, unless there's a sports event on.

Peak services are overlaid onto the standard timetable as necessary - in Belgium they are P-trains (though I don't think Belgium has lots of Swiss-style connections?) - or by adding extra coaches in some cases.
However the Swiss timetable is now so dense that I think peak trains are confined to suburban routes (which, incidentally, sometimes have reduced weekend services too).

 

[Bletchleyite]

Peak services are overlaid onto the standard timetable as necessary - in Belgium they are P-trains (though I don't think Belgium has lots of Swiss-style connections?) - or by adding extra coaches in some cases.
However the Swiss timetable is now so dense that I think peak trains are confined to suburban routes (which, incidentally, sometimes have reduced weekend services too).

In Switzerland extras tend to be R or RE (regional or regional-express) which aren't in the Takt and tend to be formed of older stock (EW I/II) and usually run DOO, so are just basic cheap capacity. They also lengthen trains, often by sticking a couple of coaches and a driving trailer or second loco on the end of a loco-hauled rake, basically using LH rakes like units.

I recall there being an evening service from Brig that was formed of two of these "mini sets", presumably to get them back to the depot.

 

[adrock1976]

Thinking about how a Taktplan would work in Great Britain, would it be better if we had progressive federalism where local all station services would be for the local councils/Passenger Transport Executives to be responsible for, County Councils (and Regional Governments based on the former European Parliament regions)possible for Regional Express services, and the Federal/National Government (ideally relocated from London to Birmingham so as to be accessible) responsible for the High Speed and traditional InterCity services?

 

[Bletchleyite]

Thinking about how a Taktplan would work in Great Britain, would it be better if we had progressive federalism where local all station services would be for the local councils/Passenger Transport Executives to be responsible for, County Councils (and Regional Governments based on the former European Parliament regions)possible for Regional Express services, and the Federal/National Government (ideally relocated from London to Birmingham so as to be accessible) responsible for the High Speed and traditional InterCity services?

There are arguments for that, but I don't think they would affect the viability of a Taktfahrplan.

 

[ChiefPlanner]

There are arguments for that, but I don't think they would affect the viability of a Taktfahrplan.

It certainly would be not high on any political agenda either........

 

[dm1]

In Switzerland extras tend to be R or RE (regional or regional-express) which aren't in the Takt and tend to be formed of older stock (EW I/II) and usually run DOO, so are just basic cheap capacity. They also lengthen trains, often by sticking a couple of coaches and a driving trailer or second loco on the end of a loco-hauled rake, basically using LH rakes like units.

I recall there being an evening service from Brig that was formed of two of these "mini sets", presumably to get them back to the depot.

There are extra S-Bahn services as well - they just run as "S" without a number, or there are also some (numbered) S-Bahn lines that only run at peak times.

EW I/II are very rare nowadays - most have been scrapped, it's generally EW IV carriages fulfilling that role.

Lengthening trains is the main way capacity is increased during the peaks - a 12 car double deck train has quite a lot of capacity! Multiple units have extra units coupled (300m is not uncommon, 400m is also possible on some lines), LHCS as you mentioned has "modules" attached consisting of a few coaches and a control car/loco (generally single deck EW IV or similar).

Something that I haven't seen in the same way in the UK is the concept of hot spares. Most major stations in Switzerland have a train (and drivers) on standby that can jump in for a delayed/faulty train at short notice to increase reliability. When connections are hourly, you can't really afford a train being cancelled (although often there are other alternatives that are slightly slower).

 

[Ianno87]

.

Something that I haven't seen in the same way in the UK is the concept of hot spares.

They do exist, for example:
-CrossCountry have a Voyager at New Street (one of the middle roads)
-Greater Anglia have a 4 car EMU at Liverpool Street off peak for each of West Anglia and Great Eastern.

 

[Bletchleyite]

Something that I haven't seen in the same way in the UK is the concept of hot spares. Most major stations in Switzerland have a train (and drivers) on standby that can jump in for a delayed/faulty train at short notice to increase reliability. When connections are hourly, you can't really afford a train being cancelled (although often there are other alternatives that are slightly slower).

Like with infrastructure that's because we like to eke out as many services as we can from what we have - resilience isn't valued the same way.

That said, there are examples of it. A spare Voyager lives in the middle road at New St, and when you've got a Brum-Euston LNR service scheduled to add another unit or two at Northampton, if it's very late they'll often send the unit there to Euston on time and cancel the other one on arrival. Helps it being at a depot, though.

Switzerland is also surrounded by countries operating international trains in that aren't quite as obsessive about punctuality, so often you'll get the "Northampton example" there - a spare set carries on in the international train's path and that either continues late or turns at the border.

Must admit I'm surprised they are now using EW IV for this, as they aren't DOO fitted, whereas EW I/II are - so you need a spare guard too.

 

[HSTEd]

Is the number of tickets and their prices issued between pairs of stations publicly available data in a spreadsheet anywhere?

I could try a superficial analysis and see if anything interesting pops out.

 

[dm1]

They do exist, for example:
-CrossCountry have a Voyager at New Street (one of the middle roads)
-Greater Anglia have a 4 car EMU at Liverpool Street off peak for each of West Anglia and Great Eastern.

That's good to hear.

Different TOCs make that much less useful however, I imagine. If an Avanti or WMT train is cancelled in New Street, having a Cross-Country hot spare doesn't really help.

 

[Austriantrain]

Coming from a country where an „integrated Takt“ (in local parlance, a regular Takt is simply a clockface timetable, it is the integration part that really makes the difference) is slowly being put into practice, just a few thoughts.

Out of curiosity, I have started to sketch what an integrated Takt for the UK would look like. Before you start criticizing me - I am perfectly aware that it is just a crayonista exercise and whatever I come up with has zero chance of working in reality. Just see it as my personal Sudoku...

However, some points: starting with the Southwest to Northeast Crosscountry is logical and probably unavoidable, since it connects all major routes from London as well as the Trans-Pennine routes. Places like Birmingham New Street, Sheffield, York etc are logical hubs. If it means that the London to Edinburgh trains leave KX at 17 or 43 past the hour instead of 0 and 30, it doesn’t really matter and will not change the usefulness or attractiveness of these services one bit.

The fact that most journey times between hubs in the UK are not multiples of 30 (journey times just under 30 minutes between hubs would be the perfect precondition for a nationwide Takt with at least a half-hourly interval on every route) is not a problem in itself either. It just means the Takt would not be perfect, but what actually is? Even the Swiss one is not perfect, and they have been building their infrastructure for Takt purposes for the last 30+ years. So you will find better solutions on some routes (eg the accelerated XC schedules Birmingham - Sheffield that run - or used to run pre Covid - a few times a day, which gives a 60 minute journey time between the two cities with Derby at half-Point) and imperfect ones on others... not a huge problem.

What I quickly ran into, however, was limited station and station approach capacity. I am not even starting with New Street... Sheffield is a good example: In a perfect Takt, XC would serve Sheffield exactly around minute 0 and 30, with TPE services built around it, London services arriving a few minutes before XC and local services arriving 10-15 minutes before the “hub“ and leaving 10-15 minutes after „the hour“. I don’t consider it feasible - even though my limited knowledge - to build such a timetable with two-track approaches on both sides and the limited number of platforms - and this is before you think of all the other factors everywhere else, such as London approaches, the Castlefield corridor (for TPE), all those flat junctions etc etc.

Trying to build a real integrated Takt in the UK would therefore most probably require station investments on a very huge scale and over a very long period. The UK network in this regard cannot be compared for instance to the German one (where they are slowly trying to integrate their regular interval timetables), where station and approach capacity are in most - of course not all - cases much higher.

Probably means that focussing on „only“ regular interval timetables (which is of course the reality on most major UK routes anyway, even though not to the same degree as the Swiss) and the most important connections (which is also done anyway) is probably the most realistic and useful way forward for the UK, especially as you focus on very frequent services (if north TPE runs every 15 minutes, perfect connections lose their usefulness as another train will come along shortly anyway).

As I said, just an outside point of view - I hope nobody feels I overstepped the mark.

 

[Bald Rick]

As I said, just an outside point of view - I hope nobody feels I overstepped the mark.

Good observations. Sheffield is indeed a significant pinch point.

 

[Ianno87]

Coming from a country where an „integrated Takt“ (in local parlance, a regular Takt is simply a clockface timetable, it is the integration part that really makes the difference) is slowly being put into practice, just a few thoughts.

Out of curiosity, I have started to sketch what an integrated Takt for the UK would look like. Before you start criticizing me - I am perfectly aware that it is just a crayonista exercise and whatever I come up with has zero chance of working in reality. Just see it as my personal Sudoku...

However, some points: starting with the Southwest to Northeast Crosscountry is logical and probably unavoidable, since it connects all major routes from London as well as the Trans-Pennine routes. Places like Birmingham New Street, Sheffield, York etc are logical hubs. If it means that the London to Edinburgh trains leave KX at 17 or 43 past the hour instead of 0 and 30, it doesn’t really matter and will not change the usefulness or attractiveness of these services one bit.

The fact that most journey times between hubs in the UK are not multiples of 30 (journey times just under 30 minutes between hubs would be the perfect precondition for a nationwide Takt with at least a half-hourly interval on every route) is not a problem in itself either. It just means the Takt would not be perfect, but what actually is? Even the Swiss one is not perfect, and they have been building their infrastructure for Takt purposes for the last 30+ years. So you will find better solutions on some routes (eg the accelerated XC schedules Birmingham - Sheffield that run - or used to run pre Covid - a few times a day, which gives a 60 minute journey time between the two cities with Derby at half-Point) and imperfect ones on others... not a huge problem.

What I quickly ran into, however, was limited station and station approach capacity. I am not even starting with New Street... Sheffield is a good example: In a perfect Takt, XC would serve Sheffield exactly around minute 0 and 30, with TPE services built around it, London services arriving a few minutes before XC and local services arriving 10-15 minutes before the “hub“ and leaving 10-15 minutes after „the hour“. I don’t consider it feasible - even though my limited knowledge - to build such a timetable with two-track approaches on both sides and the limited number of platforms - and this is before you think of all the other factors everywhere else, such as London approaches, the Castlefield corridor (for TPE), all those flat junctions etc etc.

Trying to build a real integrated Takt in the UK would therefore most probably require station investments on a very huge scale and over a very long period. The UK network in this regard cannot be compared for instance to the German one (where they are slowly trying to integrate their regular interval timetables), where station and approach capacity are in most - of course not all - cases much higher.

Probably means that focussing on „only“ regular interval timetables (which is of course the reality on most major UK routes anyway, even though not to the same degree as the Swiss) and the most important connections (which is also done anyway) is probably the most realistic and useful way forward for the UK, especially as you focus on very frequent services (if north TPE runs every 15 minutes, perfect connections lose their usefulness as another train will come along shortly anyway).

As I said, just an outside point of view - I hope nobody feels I overstepped the mark.

Very good illustration of the issues that very quickly get encountered.

 

[Austriantrain]

Good observations. Sheffield is indeed a significant pinch point.

The Swiss (and Austria has also done it on a very, very limited scale) would probably rebuild Sheffield station with least 8-9through platforms, four tracks at least to the junction towards Walsall EDIT Worksop, 2-minute-headways on all approaches, grade-separated junctions wherever there is regular service and possibly even four tracks the whole way from Dore to Meadowhall.

Probably doable with enough money, but I suppose you would have to do it all over again at Leeds, York, Newcastle etc... (and even though the stations probably are large enough, grade-separate all approaches towards New Street and Piccadilly...)

I really support integrated Takt systems, but this is far from realistic on such a scale.

 

[Bletchleyite]

The Swiss (and Austria has also done it on a very, very limited scale) would probably rebuild Sheffield station with least 8-9through platforms, four tracks at least to the junction towards Walsall, 2-minute-headways on all approaches, grade-separated junctions wherever there is regular service and possibly even four tracks the whole way from Dore to Meadowhall.

Probably doable with enough money, but I suppose you would have to do it all over again at Leeds, York, Newcastle etc... (and even though the stations probably are large enough, grade-separate all approaches towards New Street and Piccadilly...)

I really support integrated Takt systems, but this is far from realistic on such a scale.

It does show we need a change of our core approach, though, which is that building for resilience is a good thing.

 

[EastisECML]

If the UK had its own 'Takt' does that mean for a typical hub station there would be a cluster of trains arriving from the same direction close together operating parallel to each other and vice versa from the other direction? So each approach to the station could operate every track in one direction for one cluster of trains and then back in the other direction for the next cluster leaving that station? E.g. From Newcastle Central four trains arrive close together on the four track King Edward bridge at the same time as two arrive from Northumberland and two from the High Level bridge. Then those trains arriving from the KEB depart to Northumberland and over the HLB, and those trains arriving from Northumberland and the HLB depart over the KEB.

I guess of the two of the trains departing over the KEB and heading down the ECML together one could be a fast service which pulls ahead of the other, which could be a stopper which calls at Chester-le-Street. And the same for the other two KEB departures heading along the Tyne Valley.

 

[Bald Rick]

The Swiss (and Austria has also done it on a very, very limited scale) would probably rebuild Sheffield station with least 8-9through platforms, four tracks at least to the junction towards Walsall

I’d go further - what the Swiss wouldn’t have done is built two separate lines into, and two separate stations within, central Sheffield.

Also ... Walsall?

 

[Bletchleyite]

If the UK had its own 'Takt' does that mean for a typical hub station there would be a cluster of trains arriving from the same direction close together operating parallel to each other and vice versa from the other direction? So each approach to the station could operate every track in one direction for one cluster of trains and then back in the other direction for the next cluster leaving that station? E.g. From Newcastle Central four trains arrive close together on the four track King Edward bridge at the same time as two arrive from Northumberland and two from the High Level bridge. Then those trains arriving from the KEB depart to Northumberland and over the HLB, and those trains arriving from Northumberland and the HLB depart over the KEB.

There are different ways you can do it. One way is that you have a "pulse" time at main stations where everything arrives and departs, so for example you aim for all your trains to arrive between xx55 and xx58, and depart between xx02 and xx05, which is what many Swiss stations are like. That however requires some pretty hefty infrastructure. There are other ways, though, such as looking at what specific connections people are likely to want (and what journeys are already made, both by car and by train), then you can trim it down somewhat, and maybe have 2 or even 4 "pulses" an hour in which different connections meet, or even consider down to individual route level.

To consider the latter, take Lancaster. Let's say we have an hourly Manchester-Lancaster, half of which go to Windermere and half to Barrow. Typically in Switzerland you'd have the through train run fast. But the Windermere would meet an all-stations Barrow (or Cumbrian Coast) service at Lancaster, and the Barrow would meet an all-stations Windermere. And vice versa for heading south. Downside of that is that it's a 2 hour pattern rather than a 1 hour one, but it's still Takt, and indeed many DB regional Takte operate on a 2 hour pattern.

If you want an actual example of that in CH, one example is Winterthur-Konstanz and Romanshorn. The ICs alternate to each, and a local service connecting with the IC going to the other one does, too.

 

[HSTEd]

Well you can try and improve capacity by removing conflicting moves by building loop tunnels supporting existing stations, that allow all trains to enter the station from one end and leave from the other, no matter what direction they actually want to go in.

Could get pretty expensive though.

Would allow you to stack trains in platforms for pulses with far fewer constraints though.

Also building station approaches using the minimum possible ETCS-enabled headways

 

[tbtc]

Coming from a country where an „integrated Takt“ (in local parlance, a regular Takt is simply a clockface timetable, it is the integration part that really makes the difference) is slowly being put into practice, just a few thoughts.

Out of curiosity, I have started to sketch what an integrated Takt for the UK would look like. Before you start criticizing me - I am perfectly aware that it is just a crayonista exercise and whatever I come up with has zero chance of working in reality. Just see it as my personal Sudoku...

However, some points: starting with the Southwest to Northeast Crosscountry is logical and probably unavoidable, since it connects all major routes from London as well as the Trans-Pennine routes. Places like Birmingham New Street, Sheffield, York etc are logical hubs. If it means that the London to Edinburgh trains leave KX at 17 or 43 past the hour instead of 0 and 30, it doesn’t really matter and will not change the usefulness or attractiveness of these services one bit.

The fact that most journey times between hubs in the UK are not multiples of 30 (journey times just under 30 minutes between hubs would be the perfect precondition for a nationwide Takt with at least a half-hourly interval on every route) is not a problem in itself either. It just means the Takt would not be perfect, but what actually is? Even the Swiss one is not perfect, and they have been building their infrastructure for Takt purposes for the last 30+ years. So you will find better solutions on some routes (eg the accelerated XC schedules Birmingham - Sheffield that run - or used to run pre Covid - a few times a day, which gives a 60 minute journey time between the two cities with Derby at half-Point) and imperfect ones on others... not a huge problem.

What I quickly ran into, however, was limited station and station approach capacity. I am not even starting with New Street... Sheffield is a good example: In a perfect Takt, XC would serve Sheffield exactly around minute 0 and 30, with TPE services built around it, London services arriving a few minutes before XC and local services arriving 10-15 minutes before the “hub“ and leaving 10-15 minutes after „the hour“. I don’t consider it feasible - even though my limited knowledge - to build such a timetable with two-track approaches on both sides and the limited number of platforms - and this is before you think of all the other factors everywhere else, such as London approaches, the Castlefield corridor (for TPE), all those flat junctions etc etc.

Trying to build a real integrated Takt in the UK would therefore most probably require station investments on a very huge scale and over a very long period. The UK network in this regard cannot be compared for instance to the German one (where they are slowly trying to integrate their regular interval timetables), where station and approach capacity are in most - of course not all - cases much higher.

Probably means that focussing on „only“ regular interval timetables (which is of course the reality on most major UK routes anyway, even though not to the same degree as the Swiss) and the most important connections (which is also done anyway) is probably the most realistic and useful way forward for the UK, especially as you focus on very frequent services (if north TPE runs every 15 minutes, perfect connections lose their usefulness as another train will come along shortly anyway).

As I said, just an outside point of view - I hope nobody feels I overstepped the mark.

As someone who lives in Sheffield, I think you make a lot of valid points about how to start planning a proper timetable.

The main XC route seems the best place to start - put that in the timetable (with appropriate dwells at major stations, but nothing like some of the awkward ones that XC have had, as they wait to slot into the next main line that they reach/cross), and then let each region arrange its long distance services around the XC ones that are "Set In Stone" - do the regional stuff next.

The problem that I have with all of the "takt" stuff is that people start from a very well meaning position but struggle to get everything to fit as neatly as they'd like in their heads. For example, you can arrange an infrequent branch line to have good connections at the junction (e.g. Par for Newquay). But that's not possible at busy stations. So you get a situation where people complaint that the timetable is poor because there's an awkwardly short or tediously long connection between the "London" train and the "local" train but this is often because the "London" train cannot connect with every single "local" train.

For example, at Leeds, there's a two track railway towards the north west towards Skipton with branches for Harrogate/ Ilkley/ Bradford. Given the limited capacity on that line, and the need to provide a balanced service, at least a couple of those destinations are going to end up having pretty poor connections with London services in at least one direction (e.g. the half hourly Ilkley service may arrive in Leeds two minutes before the half hourly London train departs, which would be an insufficient connection, so means a thirty two minute wait).

But you've got to base a timetable along the fact that many people just make unremarkable shortish journeys on a regular basis. And that means having a well balanced service from Leeds to Shipley (balancing the Skipton and Bradford trains apart) rather than having two trains within a couple of minutes of each other and then nothing for almost half an hour, because you've written the whole timetable around optimising London (or other long distance) connections.

Or you get the alternative, where people complain that the infrequent "branch" service doesn't connect with the "right" main line service - e.g. the arguments on here about whether the Windermere shuttle should connect with trains towards Manchester/ Birmingham/ London.

Connections are one thing where it's a stand-alone branch line (like Par - Newquay), but another thing where you have services meeting at a "cross". For example, you have an hourly Birmingham - Shrewsbury - Aberystwyth service and an hourly Cardiff - Shrewsbury - Manchester service. Should they connect to permit a Cardiff - Aberystwyth service or an Aberystwyth - Manchester service? Or do you make both services wait best part of ten minutes at Shrewsbury to inconvenience people staying on the same train, for the sake of people trying to change trains in every direction at once? (e.g. the suggestion on here recently that services have a long wait at Salford to permit people from north/west of Salford to have connections to both major Manchester stations - great if you want flexibility but do passengers from Bolton to Piccadilly really want to wait in Salford for over five minutes to ensure that connections work in both directions? Should Sheffield - Lincolns services stop for ten minutes at Retford to provide a good connection in both directions with ECML services?

And then there are rural routes where you'd be a lot better forgetting about high minded concepts and focus more on having a good timed arrival in the "town" station. Much more important than a bi-hourly service.

Plus the complicated pattern of hourly services that we have because we insist on direct trains. e.g. in Sheffield you have two "semi-fast" services per hour to Manchester/ Nottingham/ Doncaster/ Leeds - if that was a half hourly Manchester - Doncaster service and a half hourly Nottingham - Leeds service then fair enough (although you might have to argue about whether to prioritise a particular connection in one direction, or occupy four of the five through platforms at Sheffield simultaneously so that you could try to arrange connections). But you can't keep all of the through services at the same time as having a well balanced half hourly service in each direction - what's the priority?

Good on paper but hard in reality.

 

[Ianno87]

The main XC route seems the best place to start - put that in the timetable (with appropriate dwells at major stations, but nothing like some of the awkward ones that XC have had, as they wait to slot into the next main line that they reach/cross), and then let each region arrange its long distance services around the XC ones that are "Set In Stone" - do the regional stuff next.

The other point about XC is that it is a reasonable place to start a timetable from, in a purely timetable sense, as it interacts with the most things, but on the assumption that all services are of equal value.

However, look at the value and volumes of individual flows and service groups, then it wouldn't win. The entire Takt would instead be built around connections to/from London mainlines, and XC would fit around that, as that in most cases will be the bigger demand.

For example, an ECML 'Takt' might be built around connections at Peterbrough, Newark, Doncaster, York, Darlington and Newcastle, with journey times between those points set at multiples of 30/60 minutes.

 

[Bletchleyite]

And then there are rural routes where you'd be a lot better forgetting about high minded concepts and focus more on having a good timed arrival in the "town" station. Much more important than a bi-hourly service.

I would say once you get below hourly that becomes the case, I've mentioned before that I think a 4 or 5-round-trip Conwy Valley service with some thought put into the timing of those trips in terms of local demand and connections would actually be a lot more useful than the pre-COVID 6-round-trip one that wasn't really timed to be useful for anything but does operate (very near to) a clean 3 hourly pattern.

I'd say LNR did that quite well with the single-unit Marston Vale timetable that was in place until recently. They did augment the service with buses, but in my observation passengers (to the extent that there were any) were using the trains and the buses were mostly running empty or very near to it. They didn't just lop one diagram, they operated less frequently but timed to be useful.

(TfW have presently reduced it to 4 - admittedly buses - but just by lopping the first and last round trips, which doesn't count )