Photo by Oran (Flickr)

Link’s vehicle shortage provides both challenges and opportunities. By deciding to batch the order for the remaining 122 cars needed to operate ST2 (Lynnwood-Overlake and Lynnwood-Angle Lake), Sound Transit chose economies of scale at the cost of limited operational flexibility in the interim years between ULink and new vehicle delivery (2016-2018). In practical terms for riders, this has meant the inability to operate all 3-car trains at weekday service levels.

Before Sound Transit selected Siemens as the vendor instead of KinkiSharyo (who built the cars you ride today), we asked that the new vehicles feature “open gangways”, nerd jargon for cars that you can walk between and through. Open gangways maximize platform space available to passengers, and are the global standard for urban rail. But in another example of negative American exceptionalism, these best practices are universally ignored here. To see open gangways in practice, Seattleites only need to visit Vancouver and ride the Canada Line.

So with this new procurement, Sound Transit has a chance to align itself with global best practice and build open cars, maximizing passenger capacity and taxpayer return on our investments in ST2 (and soon ST3). Otherwise, every 4-car train set will have 8 operator cabs forever.

In 2015, Sound Transit spokesman Bruce Gray told STB that open gangways would “limit flexibility within the fleet and the Operations and Maintenance Facility (OMF) isn’t set up to handle longer vehicles.” Asked to clarify last week, spokesman Geoff Patrick struck a similar note,

The reasons all Link trains are planned to continue featuring operator cabs at each end are not related to the incompatibility of different vehicle types with our maintenance facilities…(that would not likely be an issue for vehicles of similar length)…but rather to maintain the flexibility needed for efficient and effective train operations.

To keep operational flexibility with a fleet and system of Sound Transit’s size, we need to be able to place any light rail vehicle in any position within a trainset. Twin operator cabs at either end of the vehicle give Sound Transit this flexibility. This will be especially important when all trains are operated as four-car trains and peak-hour headways are as frequent as every three minutes. Other benefits include the ability to cut trainsets from quads to doubles or any other trainset configuration that suits the operating situation. This is also important for train rescue operations. No matter if a trainset is a single, double, triple or quad, having the ability to reverse direction from the terminus station is an absolute factor in running revenue service.

We have not analyzed how much additional passenger space could conceivably be added if Sound Transit were to adopt a framework that would be inconsistent with the vast majority of light rail systems in sacrificing this flexibility.

While operational flexibility is indeed important, whether or not it is paramount is a valid policy question. Let’s parse this statement a bit.

That would not likely be an issue for vehicles of similar length

Open gangways need not mean longer vehicles. It can mean standard length vehicles coupled and articulated, broken apart as needed for maintenance. Those asking for open gangways aren’t necessarily looking for a 400′ vehicle, but perhaps something like two 200′ vehicles.

We need to be able to place any light rail vehicle in any position within a trainset. Twin operator cabs at either end of the vehicle give Sound Transit this flexibility. This will be especially important when all trains are operated as four-car trains.

The flexibility suggested here is most applicable now, and least applicable in the full ST2 context; after Northgate opens in 2021, the plan is all 4-car trains all the time. It is reasonable to think that boosting capacity every day could be a more important policy goal than back-end operational convenience or resilience in the case of a breakdown. After all, in the case of a breakdown, non-revenue trains can be up to 8 cars in length per Kinkisharyo’s specifications for the current trains, so ST could send a tow car.

We have not analyzed how much additional passenger space could conceivably be added if Sound Transit were to adopt a framework…

It is relatively simple to get a rough idea of the capacity boost that would be possible. Link vehicles are 95′ long from coupler head to coupler head, and the diagram below shows the current fleet’s dimensions (in millimeters).

From this diagram the usable passenger space is roughly 24m, or 78 feet. Operator cabs and couplers take up the other 18′, or 19% of total car length. For a typical 4-car transit on a 400′ platform, proportional usage would be as follows:

Graphic by the Author. Lengths are rounded and simplified.

From the above graphic, fully open gangways could conceivably add 54′ of platform space, a 17% boost in passenger capacity. If trains had two 200′ cars with operator cabs and couplers in the middle, we could still add 36′, or a 12% boost. Is operational convenience worth foregoing this capacity forever?

…that would be inconsistent with the vast majority of light rail systems in sacrificing this flexibility.

This appeal to precedent makes sense in the context of low quality, low capacity North American light rail systems, but not fully grade separated Metro systems. If you view Link as closer to the latter than the former, as I do, then appeal to precedent should run in the other direction, toward the open gangway global standard. Open gangways would turn 4-car trains into “4.5 car trains” for pennies compared to the cost of lengthening platforms later. When it comes to adding capacity to a nascent rail network, there will never again be lower hanging fruit.

80 Replies to “Will Link Waste Its Capacity for the Sake of Operational Convenience?”

  1. Operational efficiency is real O&M dollars. It’s not shorthand for drivers ‘convenience’, it’s shorthand for real savings in labor hours.

    ” It is reasonable to think that boosting capacity every day could be a more important policy goal than back-end operational convenience or resilience in the case of a breakdown.” Yes, it is reasonable to think that, but we also need real dollars behind that assertion. It’s not an obvious trade-off. What’s the cost to the system to sacrifice that operational flexibility?

    If we can get as specific as “12% boost to capacity,” we should also have specifics around the operation costs of 1-cab (and zero cab) trains, not hand-waving.

      1. Bingo. The statements from ST make it obvious that they never considered open gangway and don’t care about our concerns. All new LRV’s ordered by Trimet for the past 6 years only have operator cabs at each end. They aren’t open gangway, but they are still able to add about 20 seats to each 2-car trainset that wouldn’t be there otherwise.

  2. “When it comes to adding capacity to a nascent rail network, there will never again be lower hanging fruit”

    Won’t we be buying another huge order in 5~10 years for ST3 operational needs? Maybe those can be 200′ trains for the main line, and these smaller trains can be redeployed to Issaquah-Kirkland and off-peak usage. We can even ensure the next OMF (after Bellevue) can handle 200′ trains.

    Looking further ahead, what’s the service life of these trains? When we replace these trains with driverless (and therefore cab-less) trains in 30ish years, that should be a nice boost to capacity.

    1. 30 years is the stated lifespan of the trains. Portland has had their original set for 30 years now and has no intention of replacing them anytime soon. If there are no mechanical issues with them, they could be around for way more than 30 years.

    2. Berlin S-Bahn was using certain stock from 1928 until 2003. If it’s built and maintained well and parts are still available you can make this stuff last a long time.

    3. I would guess that it’s going to be much cheaper to add autonomous capacity to trainsets we already have, rather than buy new ones. Maybe we’ll take that opportunity to correct this error, but if we make the right decision now, we’re in better shape.

      Yes, the st3 buy will happen eventually and we’ll probably get some open trains at that point, but why pass up a good idea now because we’ll get a chance to fix our mistake later? I’m not going to get a bad haircut tomorrow just because I know i’ll have a chance to fix my mistake in a few months. Why not figure out that maybe a faux-hawk is not for us right now?

      I think the 200′ option is a good compromise. The difference in platform space between two 200′ cars and one 400′ car is only 5%, and I would think that the current fleet of 95′ cars would be enough to satisfy the needs of any line that needs to run less than 200′ of train.

      Maybe when ST3 comes out, we can stretch them to 400′.

      Also, when driverless trains come to be, it’s possible a retrofit could be done for those 95′ cars to take the driver compartment bulkhead out and put in seating.

    1. Send email’s to the Sound Transit Board. I would specifically contact Rob Johnson if you live in Seattle given him addressing these. I am surprised Seattle Subway has not made this an action item. While mentioned on Facebook, this is a huge decision that needs to be scrutinized. If we get to two car coupled sets, I’d accept that as compromise but we nee more.

      1. +1. In what contingency would a 2-car train ever be inconvenient compared to a 1-car train? Just pretend it’s a one-car train, and our new train unit is twice as long as the previous.

      2. The current cars will be needed as long as we have 3-car trains, but we can phase them out over years and stop ordering them, or use them for Issaquah-Kirkland. Can they be used on Tacoma Link? Is it difficult to change the voltage, or is a one-car train too big for Tacoma’s infrastructure?

      3. The current cars will only be needed if you need one car trains. A three car train of single ended cars can be assembled out of one car plus two cars.

        Some operations are already doing this.

  3. If Portland could eliminate the cab at one end of their Siemen’s cars, why can’t Link? It can still be driven on the cabless side via a hidden control stored under the seats.

    1. Depends on how they order them. But it would only work well in a 2 or 4 car consist. You could do an 3 car with a single car tacked on one or the other end but I could see that might bring you some operational difficulties making sure you have enough equipment turned the right way.

      1. If you’re going to run trains only in 2 or 4 car consists, you might as well get double length cars. That will give most of the capacity benefits (+12% instead of +17%) without limiting yourself to a single 400 ft long train.

      2. They won’t have as much flexibility in door location on longer cars once the platform barriers are installed.

        Shorter car length also means the ability to fit the car into existing spaces. If you know a track can fit two cars but not three, you don’t have to worry about sending a train that is too long into a place that is too short for it (this was a huge issue briefly during the introduction of articulated container cars on freight railroads).

        All the same, those Alstom 100% low floor 65 mph cars for Ottawa sure look good. They’re 160 feet long and can move 300 passengers each.

      3. An alternative to platform barriers are inter car barriers on the trains themselves. Phoenix does this.

      4. @MrZ: For three car trains, you don’t need to worry too much about trains facing the wrong way. If the lone car is facing one way you add it to one end of the train, and if it is facing the other you add it to the other end of the train.

        Thee are quite a number of operations that have single cabs and arrange their trains this way.

      5. The barriers aren’t substantial. The ones I’ve seen in LA are all standard plastic traffic posts mounted on c-curb. They can be removed or modified if necessary.

      6. All Central Link platforms fit 4-car trains. The only issue of fitting is if a second train wants to stop at the platform while another train is already there *presumably disabled, and it would have to be three cars or fewer… but there won’t be any three-car trains after 2021).

      7. If you put a between-car barrier on the platform, as SoundTransit has requested, it means that you don’t have the flexibility to order a different type of car with doors in more locations as there is a section of the platform that becomes unusable.

        The SoundTransit request for proposals specifically says they want to install platform side barriers between the cars.

        In the policy letter from the Federal Transit Administration this means they will look like the final two photos of that letter.

        It’s not that they won’t be able to fit the trains into the platforms, but it just means there is a bit less flexibility on what you can order if there is an obstacle on the platform that needs to be avoided in future car designs that are longer.

      8. That second link didn’t work for some reason.

        The FTA Policy Letter shows some photos towards the bottom of platform between car barriers, which is the type ST is asking to have installed.

      9. Not being able to put a door in a place means less flexibility. You wouldn’t, for example, be able to order an Alstom Citadis without getting a special version without redesigning where the doors are.

        The more doors, the faster the train is able to move to the next station due to dwell time.

  4. 12% capacity increase. And probably a savings to be gained from simpler cars that don’t need all the electronics and controls in the extra operator cabs. Seems like a no-brainer to me. We HAVE to get this agency to start thinking bigger than “copying what Portland and San Diego do”.

    And as Babs says above, Portland has even done away with operator cabs. Why can’t a system this much busier handle it?

    1. I believe that increasing passenger capacity means that the denominator is 78 percent, and not 100 percent. 12/78 would be a 15.4 percent capacity increase and 16/78 (12 + 4 for the coupling space) would be a 20.8 percent capacity increase. It’s almost as good as adding a fifth car (25 percent increase).

  5. Does anyone make a LRV with an open gangway, or would this be something that would have to be custom ordered? I doubt the Siemens contract has that in mind but you never know. I will say the LUL “S” stock with open gangways can carry quite a crowd. Of course those trains are also 7 or 8 cars long. Like ours should have been from day 1

    1. They can certainly be made. In the US, pretty much every other city that’s built light rail has done it at-grade, so it’s designed to make sharper corners than heavy rail, for example. Also, most systems are low capacity, which I assume is why this hasn’t been a focus in North America to date.

      It becomes more obvious by the day that LRT was the wrong choice for this reason, but since we’re stuck with it now, we need to be innovative and make it work for us as well as possible.

    2. Places haven’t ordered LRVs with open gangways because once you get that much ridership, it’s time to order longer cars.

      This is why Ottawa is starting with 160 foot long 100 % low floor cars.

    3. “Does anyone make a LRV with an open gangway,”

      Strasbourg runs jumbo trams with 7 articulated segments @ 140ish feet, Dallas’s SLRTs are 120 feet (in the standard US two-room-and-a-bath format, except that the low-floor center section is 30 feet long), the “purple line” in Maryland is planning on running 5-section Urbos cars @ 136 feet, and Bombardier will sell you Flexity trams up to 148 feet. No train doors, though (if you want train doors, you need to go back 40 years and look at interurban railways and heavy transit; the vast majority of them used train doors and operator cubicles instead of full-width cabs) and the sharp curves you’d find on many of the tramways that have become LRTs are probably enough to scare the manufacturers away from a full-width passageway on anything other than an articulation.

      1. Doors at the ends of the cars so people can walk between them, like on Amtrak. That isn’t an open gangway. Open gangway is like the passage between the center section and end sections on Link or the articulation joint of a bus.

      2. Heavy rail transit can have some pretty sharp curves. CTA and NYCTA have curves so tight they need to round the ends of the cars. NYCTA is headed towards open gangways. CTA may be too tight to allow it.

      3. CTA cars are really short (40′). Same for NYC’s IRT cars (51′). Newer systems are built with wider curves to allow longer non-articulated cars (DC 75′).

        If trams and articulated buses running on streets can have open gangways, so can heavy rail transit, even the ones with sharp curves.

      4. The problem with conventionally coupled cars & tight radius curves is that the ends of the cars saw sideways when they go around the curves. That puts a lot of wear and tear on diaphragms. Articulated cars pivot at the diaphragm, so it’s not a problem.

        ST would be better off doing jumbo cars; a 4/5-section articulated car, even with cabs at each end, would give 180+ feet of passenger space and let the operations department run single car trains if they really really wanted to.

    4. The Citadis cars are modular. You can have up to five sections in a single car, all of which are pass-through. Now that’s not as long as a full four-car lashup with cabs only at the ends, but it’s “off-the-shelf” available today.

      1. Actually, for Dublin they are building a Citadis variant that is nine sections. Type 502 for the Crosstown Line. Due in 2017.

        The Siemens S70 variant used by SNCF (the Avanto) is 120 feet long. So, apparently they can make longer versions if asked – though so far nothing quite like some of the other manufacturers are offering.

  6. Are the maintenance folks angling for a turntable or something? It’s currently possible to end-for-end trains with a brief trip between switches on the main line. Operationally it would be wise to hold the next Southbound train at Sodo station while the maintenance train is being switched but it’s not that complicated.

    1. That’s my hunch too. Lots of moves on the base for everyday maintenance and cleaning are done as single cars in a counterclockwise direction and would be dangerous piloting from the rear. The current maintenance base doesn’t have the ability to turn single cars without going on the mainline, and mixed clockwise/counterclockwise movements would wreak havoc on efficient cleaning simultaneous with deployment or pull in.

      1. You don’t need to “pilot from the rear” if you have a control stand built into the “B” end of the car that has no cab. Many operations do it this way. There is typically a panel in the end seat that you can pop open with the proper key and gain access to the controls that are normally folded into the end.

        Among other things, this makes coupling the two cars at the B end vastly easier.

        It’s folded into the wall so most people don’t see the control stand as it isn’t used unless necessary.

        However, you will notice that if you look closely at Portland’s S70 cars, they have windshield wipers at the “B” end of the car that has no operator’s cab. That’s because if they do need to operate the car from the non-cab end they do still need to be able to see what is in front of them.

      2. I bet with proper coordination a car with two operators can run through the <a href="; wye switch on the main line adjacent to the maintenance facility while still allowing trains running on three-six minute headways to pass without interruption.

        It won’t be as convenient for the maintenance staff and will add a slight amount of operational complexity however we aren’t building a regional light rail network for the convenience of the maintenance staff.

      3. I’ve never seen TriMet need to make such a move. If a train comes in with pointed each way then they stay pointed each way as they go through the maintenance process. Even if one takes longer than the other you still have about half pointed one way and half pointed the other.

        It’s probably harder for TriMet that it would be with Link. TriMet has to be equally split on the direction with its single cab end cars. With Link you have various options TriMet doesn’t have:


  7. Permanent Quads are probably a waste. Operating such permanent Quads would force ST to put too many resources at the ends of the system where they would operate mainly empty.

    Basically you want heavy resources in the urban core and lighter resources on the fringes. The easiest way to do that is to get the buses out of the DSTT and run a turnback line between Stadium and University stations. That puts the resources where they are needed via frequency instead of train length. Try to solve the same problem with train length and you create waste at the periphery.

    That said, it would be nice if ST had ordered a mix of Singles and Doubles. Such a mix would allow for 2, 3 and 4-car equivalents while still gaining some efficiencies from having longer trains and fewer cabs. And we all know ST is unlikely to ever need to run singles again.

    1. Even if they did need to run singles, they’ve got a fleet already that can do that. If TriMet needs to run singles, it does so with one of the 200 or 300 series cars.

    2. After 2023 most trains will be quads all the way from Redmond and Federal Way to Lynnwood. There are no plans I’m aware of to drop cars in the middle of the line.

      During really light ridership periods Sound Transit may run 2 car trains, but those times will be in the minority due to demand on the IDS to Northgate segment.

  8. Ryan, for matters like this, right and wrong judgments are usually hindsight. Wrong implying malice aforethought. We rightly judged that our regional system would have to be built over more than one business cycle. And political climate.

    Through periods of sharply differing population growth rates and residential and employment patterns.
    Remember that when planning started, Seattle was a factory town, and today’s mall parking lots had cows in them.

    Good working definition of “light rail” could be ability to run subway, elevated, at-grade-with-crossings, painted lanes, and GP traffic on same run. For a future we knew we couldn’t know, very right choice for Central Puget Sound region at this point to point space in time.

    Right now view through windshield and all train cameras shows that if DSTT’s first load hadn’t had a dual-power trolleybus to ride, regional system would still be flip charts, lines and dots, and loud angry arguments about cost of doing anything. At meetings that couldn’t be reached on transit.

    And question, Glenn: what’s a Platform Barrier?

    Mark Dublin

  9. As much as the open gangway would be nice, 100% low floor might be even more beneficial since it would open up additional standing room. The dream scenario would be 100% low floor and open gangways like in Ottawa (thanks for the link Glenn).

    Hopefully ST gets a nice period of experience with Northgate before needing to place the big ST3 order and sees the need to order cars with increased capacity. Open gangways, 100% low floor, one operator cab per car… Something else that would help is reconfiguring the seating, at least through the center of the car, to open up standing room and make it easier to move around. No one wants to go to the center of the car to stand and then have to fight through an aisle back to the doors. 2×2 seating on the ends allows people coming from Everett or Tacoma sit while sideways seating in the center makes more standing room for the urban subway stops.

    If the ST3 order can be planned for higher capacity as needed in the core, existing stock can be used for Issaquah Kirkland and East Link which won’t have the same capacity requirements.

    1. Does anyone know if there are motors available that will give us our present performance with a low floor?


      1. The Ottawa 100% low floor car is rated for at least 63 mph (100 km / hr) but if you want to slow it down to Link standards there’s nothing stopping you from doing so.

  10. The biggest impact on capacity is going to be frequency. If they can’t quite manage a train every 3 minutes, let’s say it goes to 4, then that’s a 25% reduction in capacity (in terms of trains per hour). It’s no different than losing a full car.

    If trains can go from 3 minute headways to 2 minute headways, that’s a 50% gain in capacity. That makes 4 car trains carry as many as 6 car trains would at three minute headways.

    Let that sink in. It means that even minor delays will cause massive swings in capacity during peak times. It also means seemingly minor efficiency savings, such as lowering dwell time, could provide a huge capacity boost.

    So the ability to operate this system efficiently is basically everything. Small at grade segments need to be fought tooth and nail.

    1. Please be specific what you mean by “at-grade”. Center-of-the-street as on MLK, yes, fight like hell. However, reserved right of way with ties on the ground is a great way to save some money and gets away from the concrete forest problem of elevated railways.

      Putting Ballard Link on the ground between the rail yard and playfield is a great example, and it means that the new bridge can be in the 17th Avenue corridor putting it closer to the center of gravity of “downtown” Ballard”. It also puts the Dravus Station closer to East Magnolia where there’s much more opportunity for density than West Queen Anne. No views need be sacrificed to density.

      1. By “at grade” I mean any segment where a train shares the roadway or crosses auto traffic.

        So “on the ground” is fine, “at grade” not so much.

      2. Also depends on the segment (trunk vs branch) and how busy the cross-street is.

        East Link in Bel-Red has a few minor street crossings between Wilburton and Overlake, but is grade-separated for major street crossing. Those minor at-grade crossing should have negligible impact on frequency & reliability, and the extra cost of grade separation likely wasn’t worth it.

    2. Once the MLK segment is running through the next downtown transit tunnel, I believe the real bottleneck will be ability to move trains through the original DSTT. That is to say, dwell time at the stations closest to each other will be the limiting factor. That is why we absolutely need to get a 3-platform setup in ID/C Station, and probably Westlake Station too, with both being transfer super-hubs.

      The more doors that can open at once (i.e. on both sides of the trains to two platforms), the quicker everyone can alight and board. The fewer barriers there are between cars, the faster people will board the closest door instead of hustling to the next car.

  11. I still don’t buy the claim that we can’t run 3-car trains all day. I think ST just doesn’t want to run 3-car trains all day due to maintenance costs. I could go into the math of how many trains it actually takes to run the peak loop, but that’s another rant for another day.

    Wherever we’re getting bizarre worst-practice recommendations like building stations next to freeways, building parking garages next to all suburban stations, not building center platforms in places like Internation District / Chinatown Station, not building enough egress escalators, and buying more short LRVs with lots of space wasted on redundant driver compartments instead of building open gangways like the rest of the world, the bad decisions need to stop. Stat.

    This latest vehicle purchase was a huge blunder, executed while the transit experts were busy campaigning. Someone needs to be held accountable for not doing their due diligence homework on this purchase process, or planning for more modern maintenance facilities to accommodate open gangways.

    1. Oh, and the uniquely bizarre $5 ORCA card fees that undermine the whole ORCA project. I don’t think that came out of the same department that gave us lame excuses why we couldn’t purchase longer light rail vehicles and had to waste the space in the middle of ID/C Station with a turnback track, but it does show the shallowness of expertise somewhere in the chain of command.

      Board Member Johnson needs to stop going along to get along, and be assertive when he knows we’re throwing away hundreds of millions of dollars for the sake of bureaucratic inertia.

      1. Let’s not forget the lack of true real time arrival signs and all the BS reasons why we can’t have them.

    2. Wow. I would have expected such a scathing criticism from Mic or RossB, but if Brent has taken the gloves off then a movement is afoot. Seattle Subway has said its role has shifted from ensuring ST3’s yes vote to being its quality-control watchdog. Maybe they would want to take up some of these issues.

  12. Nice work, I like the graphic too. This is an issue that forever frustrates me about American transit systems. Stairs in the Link cars, seriously? Anyway, also consider the benefit of redesigned cars for bike trips. Right now combining Link with a bike is pretty hard – too full even during shoulder periods and not an option for many travel patterns.

    But we can provide more capacity AND accommodate bikes which fits perfectly with the openg gangway idea. A la Copenhagen: Seriously, in Copenhagen I brought my bike on the train almost every day for 5 months and it’s amazing how many people, bikesz strollers, and wheelchairs can fit in a well-defined train car. In Seattle I hated the prospect unless it was late night or early morning. Don’t be short-sighted Sound Transit!

  13. Remember low floor vehicles with open gangways will have very narrow sections between the trucks. Nobody talks about how uncomfortable 100% low floor vehicles are. This only get worse in vehicles with batteries for off-wire.

    This is why if building light rail in exclusive right-of-way you might as well use high floor vehicles with level platforms. The benefit in terms of capacity is enormous. It’s almost startling how much room there is in the vehicles in Calgary, etc.

  14. The FTA Policy letter Glenn posted regarding in-between barriers refers to “high-platform level boarding mode” operations.

    What does this mean exactly? I’m having a hard time thinking of a US light-rail system which is significantly different. CTA? MTA?

    1. SoundTransit seems to have decided they need them, as there is a request for bids out for them from October.

      1. Physically you have to have high sections in order to fit the wheel bases. If we were starting from scratch, I would have insisted on Skytrain automated but we are where we are. We need better luggage space, a little more standing room, and less operator cabs.

      2. 100% low floor cars put the motors under the seats. In some car designs you wind up with a seat with a luggage area next to it.

        While 100% low floor cars may not be quite up to the standards of SkyTrain’s open floor plan, it’s really amazing how much open space they have available. Take a look at the third photo of this design of an Alstom Citadis:ôte-d-azur-line

        With the 2+2 seats covering the wheels and the rest of the floor area left mostly open, the environment isn’t too much different than what could happen on SkyTrain.

        However, the 2+2 seating must be above the wheels and the open area and doors must be between wheel segments. The door locations don’t necessarily wind up in the same location as the high floor + low floor design that is so much more common. Thus my concern that platform barriers may limit the use of different car designs on the future.

  15. I will not comment on the topic of the post, but on premises expressed by Zach and Brent.

    Even with its 62-LRV fleet, ST could run three-car trains in the peaks if it used a seven-minute headway. This would provide more capacity than the current mix of two and three car trains. The average peak period wait time would increase to 3.5 minutes from three minutes.

    The passing track in IDS does not seem merited. It is only supposedly needed before the East Base is open. How many years after 2023 will that base open? During that time, could not the trains turn at UW or be stored overnight at OTC?

    1. I’ll have more to say later on the minimum headway allowed by the current fleet, with all 3-car trains, later. Obviously, having random-sized trains showing up, consisting of short cars, has so far worked against taking full advantage of the capacity of the train. Just board the rear car a 3-car train some time, and enjoy your stretch limo. (They’ll be running the 3rd stretch limo cars all weekend, including Mondays, for the holidays.)

      The theoretical capacity of the 3-car trains is much more than their practical capacity. Zach’s math understates the practical capacity advantages of open gangways and longer cars.

      Even with train-length announcements, we’ll still end up with some cars regularly more stuffed than others.

  16. Commenting from Vancouver here. I don’t understand why your next order shouldn’t have open gangways. The extra capacity blowes away the drawbacks….and because you already have your existing trains you still have the flexibility to run smaller trains IF you ever need to.

  17. Just to put this out there: gangways also have other advantages beyond increased capacity.

    1. It helps fare enforcement offices go between cars.

    2. It helps to provide a second way out of a train if doors malfunction – or when a door gets blocked.

    3. It allows for car even-ing for surges such as game crowds.

    4. It provides an escape when an unruly rider starts making threats or maybe if they stink!

    As a train rider in other cities for 20 years, I’ve had all of these reasons to go between cars when I could.

  18. I totally agree with your points. I personally think the 200′ option is more reasonable because it gives us the option that Geoff Patrick was bringing up on splitting the cars in two when necessary. The real question is, why is Sound Transit so unconfident in their reliability? Seriously, if they had designed their system completely grade separated, they probably wouldn’t have to factor the “what if?” scenario into every idea proposed. As much as I love Link, their trains have reliability problems, so a 400′ train option wouldn’t be viable. They should be really focusing on redesigning their train layouts and maximizing capacity. Look at Taipei’s MRT System for example with the seats on the sides of the car.

    Another thing we can take from Taipei’s system are the Platform Barriers. So far Sound Transit hasn’t had that much of a problem with people falling onto the tracks, but if they want to keep people safe on their platforms, they should do it right. Taipei has full and half barriers on their platform that light up when a train is arriving. Sound Transit should really learn from other cities and use their money wisely.

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