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How Many Tracks Do Train Stations Need?

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How Many Tracks Do Train Stations Need?

A brief discussion on Reddit about my post criticizing Penn Station expansion plans led me to write a very long comment, which I’d like to hoist to a full post explaining how big an urban train station needs to be to serve regional and intercity rail traffic. The main principles are,

  • Good operations can substitute for station size, and it’s always cheaper to get the system to be more reliable than to build more tracks in city center.
  • Through-running reduces the required station footprint, and this is one of the reasons it is popular for urban commuter rail systems.
  • The simpler and more local the system is, the fewer tracks are needed: an urban commuter rail system running on captive tracks with no sharing tracks with other traffic and with limited branching an get away with smaller stations than an intercity rail station featuring trains from hundreds of kilometers away in any direction.

The formula for minimum headways

On subways, where usually the rush hour crunches are the worst, trains in large cities run extremely frequently, brushing up against the physical limitation of the tracks. The limit is dictated by the brick wall rule, which states that the signal system must at any point assume that the train ahead can turn into a brick wall and stop moving and the current train must be able to brake in time before it reaches it. Cars, for that matter, follow the same rule, but their emergency braking rate is much faster, so on a freeway they can follow two seconds apart. A metro train in theory could do the same with headways of 15 seconds, but in practice there are stations on the tracks and dealing with them requires a different formula.

With metro-style stations, without extra tracks, the governing formula is,

mbox{headway } = mbox{stopping time } + mbox{dwell time } + mbox{platform clearing time }

Platform clearing time is how long it takes the train to clear its own length; the idea of the formula is that per the brick wall rule, the train we’re on needs to begin braking to enter the next station only after the train ahead of ours has cleared the station.

But all of this is in theory. In practice, there are uncertainties. The uncertainties are almost never in the stopping or platform clearing time, and even the dwell time is controllable. Rather, the schedule itself is uncertain: our train can be a minute late, which for our purpose as passengers may be unimportant, but for the scheduler and dispatcher on a congested line means that all the trains behind ours have to also be delayed by a minute.

What this means that more space is required between train slots to make schedules recoverable. Moreover, the more complex the line’s operations are, the more space is needed. On a metro train running on captive tracks, if all trains are delayed by a minute, it’s really not a big deal even to the control tower; all the trains substitute for one another, so the recovery can be done at the terminal. On a mainline train running on a national network in which our segment can host trains to Budapest, Vienna, Prague, Leipzig, Munich, Zurich, Stuttgart, Frankfurt, and Paris, trains cannot substitute for one another – and, moreover, a train can be easily delayed 15 minutes and need a later slot. Empty-looking space in the track timetable is unavoidable – if the schedule can’t survive contact with the passengers, it’s not a schedule but crayon.

How to improve operations

In one word: reliability.

In two words: more reliability.

Because the main limit to rail frequency on congested track comes from the variation in the schedule, the best way to increase capacity is to reduce the variation in the schedule. This, in turn, has two aspects: reducing the likelihood of a delay, and reducing the ability of a delay to propagate.

Reducing delays

The central insight about delays is that they may occur anywhere on the line, roughly in proportion to either trip time or ridership. This means that on a branched mainline railway network, delays almost never originate at the city center train station or its approaches, not because that part of the system is uniquely reliable, but because the train might spend five minutes there out of a one-hour trip. The upshot is that to make a congested central segment more reliable, it is necessary to invest in reliability on the entire network, most of which consists of branch segments that by themselves do not have capacity crunches.

The biggest required investments for this are electrification and level boarding. Both have many benefits other than schedule reliability, and are underrated in Europe and even more underrated in the United States.

Electrification is the subject of a TransitMatters report from last year. As far as reliability is concerned, the LIRR and Metro-North’s diesel locomotives average about 20 times the mechanical failure rate of electric multiple units (source, PDF-pp. 36 and 151). It is bad enough that Germany is keeping some outer regional rail branches in the exurbs of Berlin and Munich unwired; that New York has not fully electrified is unconscionable.

Level boarding is comparable in its importance. It not only reduces dwell time, but also reduces variability in dwell time. With about a meter of vertical gap between platform and train floor, Mansfield has four-minute rush hour dwell times; this is the busiest suburban Boston commuter rail station at rush hour, but it’s still just about 2,000 weekday boardings, whereas RER and S-Bahn stations with 10 time the traffic hold to a 30-second standard. This also interacts positively with accessibility: it permits passengers in wheelchairs to board unaided, which both improves accessibility and ensures that a wheelchair user doesn’t delay the entire train by a minute. It is fortunate that the LIRR and (with one peripheral exception) Metro-North are entirely high-platform, and unfortunate that New Jersey Transit is not.

Reducing delay propagation

Even with reliable mechanical and civil engineering, delays are inevitable. The real innovations in Switzerland giving it Europe’s most reliable and highest-use railway network are not about preventing delays from happening (it is fully electrified but a laggard on level boarding). They’re about ensuring delays do not propagate across the network. This is especially notable as the network relies on timed connections and overtakes, both of which require schedule discipline. Achieving such discipline requires the following operations and capital treatments:

  • Uniform timetable padding of about 7%, applied throughout the line roughly on a one minute in 15 basis.
  • Clear, non-discriminatory rules about train priority, including a rule that a train that’s more than 30 minutes loses all priority and may not delay other trains at junctions or on shared tracks.
  • A rigid clockface schedule or Takt, where the problem sections (overtakes, meets, etc.) are predictable and can receive investment. With the Takt system, even urban commuter lines can be left partly single-track, as long as the timetable is such that trains in opposite directions meet away from the bottleneck.
  • Data-oriented planning that focuses on tracing the sources of major delays and feeding the information to capital planning so that problem sections can, again, receive capital investment.
  • Especial concern for railway junctions, which are to be grade-separated or consistently scheduled around. In sensitive cases where traffic is heavy and grade separation is too expensive, Switzerland builds pocket tracks at-grade, so that a late train can wait for a slot without delaying cross-traffic.

So, how big do train stations need to be?

A multi-station urban commuter rail trunk can get away with metro-style operations, with a single station track per approach track. However, the limiting factor to capacity will be station dwell times. In cases with an unusually busy city center station, or on a highly-interlinked regional or intercity network, this may force compromises on capacity.

In contrast, with good operations, a train station with through-running should never need more than two station tracks per approach track. Moreover, the two station tracks that each approach track splits into should serve the same platform, so that if there is an unplanned rescheduling of the train, passengers should be able to use the usual platform at least. Berlin Hauptbahnhof’s deep tracks are organized this way, and so is the under-construction Stuttgart 21.

Why two? First, because it is the maximum number that can serve the same platform; if they serve different platforms, it may require lengthening dwell times during unscheduled diversions to deal with passenger confusion. And second, because every additional platform track permits, in theory, an increase in the dwell time equal to the minimum headway. The minimum headway in practice is going to be about 120 seconds; at rush hour Paris pushes 32 trains per hour on the shared RER B and D trunk, which is not quite mainline but is extensively branched, but the reliability is legendarily poor. With a two-minute headway, the two-platform track system permits a straightforward 2.5-minute dwell time, which is more than any regional railway needs; the Zurich S-Bahn has 60-second dwells at Hauptbahnhof, and the Paris RER’s single-level trains keep to about 60 seconds at rush hour in city center as well.

All of this is more complicated at a terminal. In theory the required number of tracks is the minimum turn time divided by the headway, but in practice the turn time has a variance. Tokyo has been able to push station footprint to a minimum, with two tracks at Tokyo Station on the Chuo Line (with 28 peak trains per hour) and, before the through-line opened, four tracks on the Tokaido Main Line (with 24). But elsewhere the results are less optimistic; Paris is limited to 16-18 trains per hour at the four-track RER E terminal at Saint-Lazare.

At Paris’s levels of efficiency, which are well below global best practices, an unexpanded Penn Station without through-running would still need two permanent tracks for Amtrak, leaving 19 tracks for commuter traffic. With the Gateway tunnel built, there would be four two-track approaches, two from each direction. The approaches that share tracks with Amtrak (North River Tunnels, southern pair of East River Tunnels) would get four tracks each, enough to terminate around 18 trains per hour at rush hour, and the approaches that don’t would get five, enough for maybe 20 or 22. The worst bottleneck in the system, the New Jersey approach, would be improved from today’s 21 trains per hour to 38-40.

A Penn Station with through-running does not have the 38-40 trains per hour limit. Rather, the approach tracks would become the primary bottleneck, and it would take an expansion to eight approach tracks on each side for the station itself to be at all a limit.

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FIFA 23 lets you turn off commentary pointing out how bad you are

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FIFA 23 lets you turn off commentary pointing out how bad you are
A player shouldering the ball



(Image credit: EA)

FIFA 23 might be the best game soccer game yet for terrible sports fans, as it lets you turn off commentary that criticizes your bad playing.

Now that the early access FIFA 23 release time has passed, EA Play and Xbox Game Pass Ultimate subscribers can hop into the game ahead of its full release. But as Eurogamer (opens in new tab) spotted, they’ll find a peculiar option waiting for them.

FIFA 23 includes a toggle to turn off ‘Critical Commentary’. The setting lets you silence all negative in-match comments made about your technique, so you can protect your precious ego even when you miss an open goal or commit an obvious foul. The more positive commentary won’t be affected. 

Spare your feelings

A player dribbling the ball in FIFA 23

(Image credit: EA)

The feature looks tailored toward children and new players, who don’t want to have their confidence wrecked within mere minutes of picking up the controller. But even experienced players who just so happen to be terrible at the game might benefit.

It’s not perfect, though. According to Eurogamer, the feature didn’t seem to work during a FIFA Ultimate Team Division Rivals match, with critical comments slipping through the filter. Still, who hasn’t benefited from a light grilling every now and then?

Polite commentary isn’t the only new addition in FIFA 23. It’s the first game in the series to include women’s club football teams, and fancy overhauled animations that take advantage of the PS5 and Xbox Series X|S’s new-gen hardware. EA will be hoping to end on a high, as FIFA 23 will be the last of its soccer games to release with the official FIFA licence.

If disabling critical commentary doesn’t improve your soccer skills, maybe building a squad of Marvel superheroes will. Although you might not do much better with Ted Lasso wandering the pitch.

FIFA 23 is set to fully release this Friday, September 30.

Callum is TechRadar Gaming’s News Writer. You’ll find him whipping up stories about all the latest happenings in the gaming world, as well as penning the odd feature and review. Before coming to TechRadar, he wrote freelance for various sites, including Clash, The Telegraph, and Gamesindustry.biz, and worked as a Staff Writer at Wargamer. Strategy games and RPGs are his bread and butter, but he’ll eat anything that spins a captivating narrative. He also loves tabletop games, and will happily chew your ear off about TTRPGs and board games. 

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Google Pixel 7 price leak suggests Google is totally out of touch

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Google Pixel 7 price leak suggests Google is totally out of touch
The backs of the Pixel 7 and the Pixel 7 Pro



(Image credit: Google)

We’re starting to hear more and more Google Pixel 7 leaks, with the launch of the phone just a week away, but tech fans might be getting a lot of déjà vu, with the leaks all listing near-identical specs to what we heard about the Pixel 6 a year ago.

It sounds like the new phones – a successor to the Pixel 6 Pro is also expected – could be very similar to their 2021 predecessors. And a new price leak has suggested that the phones’ costs could be the same too, as a Twitter user spotted the Pixel 7 briefly listed on Amazon (before being promptly taken down, of course).

Google pixel 7 on Amazon US. $599.99.It is still showing up in search cache but the listing gives an error if you click on it. We have the B0 number to keep track of though!#teampixel pic.twitter.com/w5Z09D28YESeptember 27, 2022

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According to these listings, the Pixel 7 will cost $599 while the Pixel 7 Pro will cost $899, both of which are identical to the Pixel 6 and Pixel 6 Pro starting prices. The leak doesn’t include any other region prices, but in the UK the current models cost £599 and £849, while in Australia they went for AU$999 and AU$1,299.

So it sounds like Google is planning on retaining the same prices for its new phones as it sold the old ones for, a move which doesn’t make much sense.


Analysis: same price, new world

Google’s choice to keep the same price points is a little curious when you consider that the specs leaks suggest these phones are virtually unchanged from their predecessors. You’re buying year-old tech for the same price as before.

Do bear in mind that the price of tech generally lowers over time, so you can readily pick up a cheaper Pixel 6 or 6 Pro right now, and after the launch of the new ones, the older models will very likely get even cheaper.

But there’s another key factor to consider in the price: $599 might be the same number in 2022 as it was in 2021, but with the changing global climate, like wars and flailing currencies and cost of living crises, it’s a very different amount of money.

Some people just won’t be willing to shell out the amount this year, that they may have been able to last year. But this speaks to a wider issue in consumer tech.

Google isn’t the only tech company to completely neglect the challenging global climate when pricing its gadgets: Samsung is still releasing super-pricey folding phones, and the iPhone 14 is, for some incomprehensible reason, even pricier than the iPhone 13 in some regions. 

Too few brands are actually catering to the tough economic times many are facing right now, with companies increasing the price of their premium offerings to counter rising costs, instead of just designing more affordable alternatives to flagships.

These high and rising prices suggest that companies are totally out of touch with their buyers, and don’t understand the economic hardship troubling many.

We’ll have to reach a breaking point sooner or later, either with brands finally clueing into the fact that they need to release cheaper phones, or with customers voting with their wallets by sticking to second-hand or refurbished devices. But until then, you can buy the best cheap phones to show that cost is important to you.

Tom’s role in the TechRadar team is to specialize in phones and tablets, but he also takes on other tech like electric scooters, smartwatches, fitness, mobile gaming and more. He is based in London, UK.

He graduated in American Literature and Creative Writing from the University of East Anglia. Prior to working in TechRadar freelanced in tech, gaming and entertainment, and also spent many years working as a mixologist. Outside of TechRadar he works in film as a screenwriter, director and producer.

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DisplayMate awards the “Best Smartphone Display” title to the iPhone 14 Pro Max

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DisplayMate awards the “Best Smartphone Display” title to the iPhone 14 Pro Max

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