Countdown to next train in seconds

[Pdf]

I was travelling in Barcelona recently and saw that the passenger information system on their metro system tells you when the next train is expected to the second, rather than the minute precision that the underground uses. Would this be technically feasible with the train tracking system used by LU? Do you think it would be beneficial?

 

[rebmcr]

Would this be technically feasible with the train tracking system used by LU?

On some lines, probably.

Do you think it would be beneficial?

I don't think so.

 

[bramling]

I was travelling in Barcelona recently and saw that the passenger information system on their metro system tells you when the next train is expected to the second, rather than the minute precision that the underground uses. Would this be technically feasible with the train tracking system used by LU? Do you think it would be beneficial?

Yes it would certainly be possible on some of the more recently resignalled lines. Indeed the system used already calculates this, and uses it for internal purposes.

I’m not sure there would be any benefit to the passenger, as in most cases things aren’t going to run to that level of accuracy. Even at a terminus it’s quite probable that once the calculated departure time is reached the train might not yet depart - perhaps because the route isn’t yet clear, or the driver isn’t in position and ready.

What we have now seems to work reasonably well, even if on the Victoria Line one seems to have to add a minute to what is displayed!

 

[Magdalia]

This reminds me of my only visit to Prague, not long after the Berlin Wall came down. I have two very strong memories of the Prague Metro. One was that the passenger information systems displayed a running clock showing the elapsed time since the last train departed, not the expected time to the next train's arrival, with the clear assumption that the trains "ran like clockwork". The other was that every step on every escalator was numbered, and one escalator that I used had more than 500 steps.

 

[JaJaWa]

Taipei uses seconds too – 5 second intervals except the Brown line (VAL) which uses 1 second intervals

 

[Mojo]

May be off topic for this thread or worthy of a new topic but I’ve noticed from the ex-Soviet Metro systems I’ve used (Tbilisi and Kyiv), as well as pictures I’ve seen from Moscow, that they have a clock on the headwall above the track that seems to display the time since the last train, counting up in minutes and seconds. Is this provided for the train drivers to manage their own headways and dwell time, or is it for customers to guess how long until the next train, or for some other purpose?

 

[dm1]

It's for drivers to manage headway in real time. They also get told by control to hold to a specific headway or time if necessary.

In the peaks watching the 90s headways is impressive, and as a passenger you get a feel for roughly what the headway will be at different times of day, so know roughly when to expect the next train.

Trains are deliberately scheduled slightly slower than the minimum time it takes to run between stations, so that if there is a delay for any reason (e.g. passengers blocking doors) it can be caught up by the next station.

 

[43066]

What we have now seems to work reasonably well, even if on the Victoria Line one seems to have to add a minute to what is displayed!

In my experience there’s no minute longer than a Northern Line minute .

 

[bramling]

In my experience there’s no minute longer than a Northern Line minute .

One of these days it’s actually something I’m going to look in to as it’s been bugging me for the best part of a decade, but the Vic Line platform indicators seem to work slightly differently to everywhere else, which is quite feasible as their line upgrade was done by a different team / supplier to everywhere else.

The way anywhere else seems to work is once “1 min” is displayed this means it is essentially that time until the train should depart. On the Vic once this has elapsed there seems to be a further minute with no countdown displayed before the train actually materialises. So it either works on the basis of the train’s predicted *arrival*, or they round the prediction down whereas all the other lines round up (so on the Vic “1 min” can be anything up to 1:59, whereas on other lines it is anything up to 1:00).

The reason why all this bugs me? All the times I’ve waited on the Victoria Line platform at King’s Cross and the second train is shown as “1 min”, yet it invariably ends up being rather longer. I suppose people used to hourly or worse services in rural parts of the country would raise an eyebrow at all this!

 

[Taunton]

This reminds me of my only visit to Prague, not long after the Berlin Wall came down. I have two very strong memories of the Prague Metro. One was that the passenger information systems displayed a running clock showing the elapsed time since the last train departed, not the expected time to the next train's arrival, with the clear assumption that the trains "ran like clockwork". The other was that every step on every escalator was numbered, and one escalator that I used had more than 500 steps.

All standard features of Russian Metros. The Soviet Union designed and built the Prague Metro, and supplied the rolling stock, all to their normal standards. The time since last departure, on a large digital display on the headwall, is useful to passengers, particularly where the system runs accurate headways (certainly more than London - I'm not quite sure how they achieve it), and drivers use it to speed up or slow down, by varying the coasting points, though the latter seem limited on their Metros as well, it's normally full motoring followed by full rheostatic braking. Regulars get to know the intervals of trains, and compared to all the countdown logic needed it's a very simple system, the clock just having a trip on the trackside.

 

[rebmcr]

The triangle-shaped distribution of interchange stations in the central area is also a hallmark of Soviet metro design, as seen in several Eastern Bloc cities.

 

[JaJaWa]

May be off topic for this thread or worthy of a new topic but I’ve noticed from the ex-Soviet Metro systems I’ve used (Tbilisi and Kyiv), as well as pictures I’ve seen from Moscow, that they have a clock on the headwall above the track that seems to display the time since the last train, counting up in minutes and seconds. Is this provided for the train drivers to manage their own headways and dwell time, or is it for customers to guess how long until the next train, or for some other purpose?

The East Rail line in HK also had these – they had digital clocks counting up, placed in view of the drivers cab. They seem to have gone since they replaced the trains / signalling.

 

[John-H]

The East Rail line in HK also had these – they had digital clocks counting up, placed in view of the drivers cab. They seem to have gone since they replaced the trains / signalling.

St Petersburg had these counters on all of their stations. Usually the departure is 2:20 after the previous one, and quite consistent, but late at night I have seen service intervals as long as 4:30. Still amazing service.

 

[Taunton]

The Metro in Paris likewise has/had them, mounted slightly into the tunnel at stations and counting up the seconds. I believe also that London Transport may have had a shot at them long ago, for I recall an article, naming them as "Headway Clocks", and saying they didn't work well for them. I wonder how Eastern Europe manages well therefore.

 

[TRAX]

The Metro in Paris likewise has/had them, mounted slightly into the tunnel at stations and counting up the seconds.

That’s for the driver though, and is quite a complex system of timekeeping, with not much to do with the actual waiting time and intervals.

 

[The exile]

One of these days it’s actually something I’m going to look in to as it’s been bugging me for the best part of a decade, but the Vic Line platform indicators seem to work slightly differently to everywhere else, which is quite feasible as their line upgrade was done by a different team / supplier to everywhere else.

The way anywhere else seems to work is once “1 min” is displayed this means it is essentially that time until the train should depart. On the Vic once this has elapsed there seems to be a further minute with no countdown displayed before the train actually materialises. So it either works on the basis of the train’s predicted *arrival*, or they round the prediction down whereas all the other lines round up (so on the Vic “1 min” can be anything up to 1:59, whereas on other lines it is anything up to 1:00).

The reason why all this bugs me? All the times I’ve waited on the Victoria Line platform at King’s Cross and the second train is shown as “1 min”, yet it invariably ends up being rather longer. I suppose people used to hourly or worse services in rural parts of the country would raise an eyebrow at all this!

At least they’re not displaying “arrived” before the train is even in sight like some places on the “big” railway (I’m looking at you, Bristol Parkway!)

 

[AlbertBeale]

In my experience there’s no minute longer than a Northern Line minute .

I've always thought that the Bakerloo Line minutes were rather less than real minutes...

 

[MikeWh]

At least they’re not displaying “arrived” before the train is even in sight like some places on the “big” railway (I’m looking at you, Bristol Parkway!)

The "arrived" display is triggered by the train entering the section of track containing the platform. That can in some cases be quite a way away. I don't know about Bristol Parkway, but the curve before the bridge on the up platform at Crayford means that the train is always out of sight when first shown as arrived.

 

[Snow1964]

I suppose adding seconds could be useful if it was consistently used as a countdown to start of door closing sequence

I have never been a fan of advertising a train at X then closing door 30-45 seconds earlier,

 

[Bald Rick]

If you study the Barca metro countdown clocks closely, you’ll see that they don’t always count down! I’ve regularly seen them extend out by a minute or more.

 

[Brooke]

In my experience there’s no minute longer than a Northern Line minute .

Same with the District Line! I regularly use Mile End station, and the District can say e.g. 1 min while the adjacent Central says 2 mins. Often the Central train arrives first!

 

[Bletchleyite]

I was travelling in Barcelona recently and saw that the passenger information system on their metro system tells you when the next train is expected to the second, rather than the minute precision that the underground uses. Would this be technically feasible with the train tracking system used by LU? Do you think it would be beneficial?

I've seen these and they're like Microsoft minutes, they go up and down all the time. So not of much value really.

 

[AlbertBeale]

Not an arrival countdown, but on the digital "clock" on one of the Moorgate SSL platforms the other day, they had a little seconds figure along with the hour and minute. Is that routine?? Have I just not noticed before?

 

[jumble]

There are a lot of places where the Boards are not at all accurate
Harrow on the Hill regularly has phantom trains
ie
1 Uxbridge 1 minute
2 Uxbridge 2 minutes

 

[rebmcr]

Same with the District Line! I regularly use Mile End station, and the District can say e.g. 1 min while the adjacent Central says 2 mins. Often the Central train arrives first!

The District PIS between Stepney Green and Upminster is, without exaggeration, powered by guesswork. The signalling is planned to be upgraded — first between Stepney Green and Becontree, then all the way to Upminster — which follow on from similar sections of the Circle line already upgraded. It will result in precise information about train arrivals on apps, websites, and platforms (no more 'Check front of train').

Your upgrade was intended for July just gone, but has been pushed to next year because of software bugs found in the previous section around Earl's Court. This thread has full information.

 

[Brooke]

The District PIS between Stepney Green and Upminster is, without exaggeration, powered by guesswork. The signalling is planned to be upgraded — first between Stepney Green and Becontree, then all the way to Upminster — which follow on from similar sections of the Circle line already upgraded. It will result in precise information about train arrivals on apps, websites, and platforms (no more 'Check front of train').

Your upgrade was intended for July just gone, but has been pushed to next year because of software bugs found in the previous section around Earl's Court. This thread has full information.

Thanks - very interesting. Last week we were back to ‘Check Front of Train’ for virtually all trains - and with times shown of 10+ mins, even when trains were in sight. I live in hope of something more accurate!

 

[LU_timetabler]

The Victoria Line is scheduled by depart to arrive at each station, whereas the other lines are scheduled generally only by departure time, with the dwell time at the station built into the run time, other than when extra station hold time is required for service smoothing / timetabled driver change-over's, etc. When the timetable would indicate the extra platform stand time. IF that helps explain the difference I don't know?

 

[ThisIsSurbiton]

I was travelling in Barcelona recently and saw that the passenger information system on their metro system tells you when the next train is expected to the second

As @Bletchleyite says, they're not very accurate - maybe more so on the automated lines - and regularly refresh to change their minds. They also change to ENTRA as the train is approaching so it's hard to say when they would have reached 0.

The Metro in Paris likewise has/had them, mounted slightly into the tunnel at stations and counting up the seconds

The ones I've seen had four full times (hh : mm : ss), according to the timetable type the train was on (something like peak, contra-peak, daytime, evening or similar). They showed the time the train was scheduled to have left its origin station, so the driver would look for that same time at each subsequent station. Quite an ingenious way to do it without much technology.

The automated lines in Paris now have platform displays with a ten-second resolution.

 

[Taunton]

The Paris Metro (working) timetable is quite unlike anything elsewhere. It does have those four sets of running times, and separately has four sets of train headways on any line, where the 'peak' service becomes progressively less frequent in the summer, with less trains in circuit, when half of Paris takes off for holidays, and presumably the Metro drivers likewise. I seem to recall the timetable times and headways have a resolution down to 6 seconds, being 0.1 of a minute.

Only in France ...

 

[321over360]

Same with the District Line! I regularly use Mile End station, and the District can say e.g. 1 min while the adjacent Central says 2 mins. Often the Central train arrives first!

District Line destination boards at Mile End never work properly, I've changed over from the Central to the District going west and the first train kept getting longer until it arrived then one randomly showed up. And this has been an ongoing issue at Mile End, there's been trains advertised as going to Hammersmith (ie H&C) and a District Line comes in