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Old March 1st, 2007, 03:27 AM   #361
UrbanBen
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Originally Posted by alta-bc View Post
So Seattle can run 4 car trains (380ft) at a design capacity of 800 passengers total, every two minutes. Seattle is predicting 42,500 daily ridership by 2020 for the initial segment.

Vancouver can run 2 car trains (113ft) at a design capacity of 334 passengers total every 1 and a half minutes. Vancouver is predicting 140,000 to 150,000 daily ridership by 2020.

According to these numbers, either Seattle is totally overbuilding the LRT, or Vancouver is in for a system that is bursting at its seams from day one.
It's a little of both. Seattle won't be running 800-person trains to begin with, they'll be running 400-person (two car) trains. 42,500 passengers is with Initial Segment alone - we'll be looking at nearly 300,000 passengers per day with Sound Transit 2 built out, so we'll need that capacity.

Vancouver's 2020 is significantly lower than Seattle's 2020. Canada Line isn't being built for expansion, and Link is.
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Old March 1st, 2007, 03:29 AM   #362
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Originally Posted by sequoias View Post
I read somewhere that once the ridership grows there should be a minimum of 2 minute headways down from the opening of 6 minute headways in 2009 during peak hours. I can't imagine lot of trains passing the intersections in Sodo and Rainier Valley. Wouldn't that cause lot of congestion in car traffic when trains pass every 2 minutes? I wish it was grade seperated from traffic, though.
Phew. No way - Rainier Valley likely won't ever see headways lower than 5 minutes (they're not planned). Trains will operate at higher frequency through downtown, but most of those trains will then head to the eastside over I-90.
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Old March 1st, 2007, 03:30 AM   #363
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Originally Posted by mr.x View Post
The Seattle line has drivers right? That means with longer platforms, you can add capacity by having longer trains by building longer platforms instead of hiring more drivers....which is more expensive and complex.....which also means frequency won't likely change.
Mr. X, frequency is planned to go up to every 2.4 minutes through downtown, according to ST's 2005 long range plan.

(Hey, sorry if I'm flooding the thread - hopefully commenters are getting notification that they've been replied to.)
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Old March 1st, 2007, 07:15 AM   #364
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seattle has never really had anything like the LRT so its really an unknown for the people of the city and the impact it will have in the coming years

currently people may say nah i probably won;t use it but oen day when they are sitting stuck in traffic and see the thing whiz by they may change their mind

and once given a chance to see just how good a service it can be they may change their minds
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Old March 1st, 2007, 05:36 PM   #365
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I saw that many posts in this thread are about accidents with light rail trains.

Those accidents are tragic, and one should do actively something in order to reduce their numbers. But to use it as argument why public transport is "dangerous" is in my eyes dead wrong. I am not sure anyone did so, but just in case someone did.

I think the number of accidents will decreas once people are used to this new form of transport.

My question would be, how fast those ligt railway trains cross intersections? And are the intersections kept free for those trains in block, in order to be able to drive through without even once stopping in front of a crossing? Or is it just that those trains get green light first, but have also wait from time to time?


I just have the comparision with Vienna. It has one of the largest tram networks in the world. No idea how many crossings, but a vast number for sure. Accidents with trams happen every now and then. Sometimes they are letal. But I can not remember that it is less secure than cars.

Its simple, if you cross railways (no matter if you are a biker, pedestrian or car driver), you [I]always[I] have to look if something is approaching. If you do so nothing can happen.
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Old March 1st, 2007, 09:43 PM   #366
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Originally Posted by Slartibartfas View Post
I saw that many posts in this thread are about accidents with light rail trains.

Those accidents are tragic, and one should do actively something in order to reduce their numbers. But to use it as argument why public transport is "dangerous" is in my eyes dead wrong. I am not sure anyone did so, but just in case someone did.

I think the number of accidents will decreas once people are used to this new form of transport.

My question would be, how fast those ligt railway trains cross intersections? And are the intersections kept free for those trains in block, in order to be able to drive through without even once stopping in front of a crossing? Or is it just that those trains get green light first, but have also wait from time to time?


I just have the comparision with Vienna. It has one of the largest tram networks in the world. No idea how many crossings, but a vast number for sure. Accidents with trams happen every now and then. Sometimes they are letal. But I can not remember that it is less secure than cars.

Its simple, if you cross railways (no matter if you are a biker, pedestrian or car driver), you [I]always[I] have to look if something is approaching. If you do so nothing can happen.
There's another interesting aspect of mass transit and safety that I think a lot of people miss:

A handful of accidents with two or three fatalities over many years (like Portland or Denver) is vastly lower than the dozens of annual fatalities you'd get with the same number of people in cars.

It's all about asking the right question: For the number of people who switch to transit when you install rail, is it safer to have them on a light rail train at-grade, or in their cars? Frame the argument in an appropriate context and the debate disappears.
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Old March 2nd, 2007, 07:09 PM   #367
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Quote:
Originally Posted by UrbanBen View Post
Mr. X, frequency is planned to go up to every 2.4 minutes through downtown, according to ST's 2005 long range plan.

(Hey, sorry if I'm flooding the thread - hopefully commenters are getting notification that they've been replied to.)
Oh this is exciting news! I think I understand the system now.

So if all built out, the trains with frequencies of 5 minutes in Rainier Valley and bellevue will "merge" at Int'l Station and continue north at 2.5 minute frequencies? Sweeet. By then, hopefully the buses will have cleared out because I can't imagine short frequencies mixed with buses in the bus tunnel.

So in theory, at Northgate, you can board an "airport train" or a "bellevue train?"

Phew. Now I'm not worried anymore about Rainier Valley ruining everything.
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Old March 3rd, 2007, 02:22 AM   #368
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Originally Posted by kub86 View Post
Oh this is exciting news! I think I understand the system now.

So if all built out, the trains with frequencies of 5 minutes in Rainier Valley and bellevue will "merge" at Int'l Station and continue north at 2.5 minute frequencies? Sweeet. By then, hopefully the buses will have cleared out because I can't imagine short frequencies mixed with buses in the bus tunnel.

So in theory, at Northgate, you can board an "airport train" or a "bellevue train?"

Phew. Now I'm not worried anymore about Rainier Valley ruining everything.
Haha! Glad I've allayed your fears.

At build-out (according to the '05 long range plan), you'll be able to board three kinds of trains at Everett, southbound: Tacoma trains (via SeaTac) every 5 minutes, Redmond trains (via Bellevue) every 7 (maybe 7.5?) minutes, and Issaquah trains (that hit Mercer Island and Eastgate) every 15 minutes. Combined, this gives you a little over 2 minutes.

I believe you're right that buses will be kicked out of the tunnel as headways decrease - I've heard that from more than one person. At that point, I should hope to see 3rd Avenue closed to cars entirely, but that's just me.
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Old March 3rd, 2007, 11:56 PM   #369
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UrbanBen,

Thanks for filling in some more details.

I'm not that familiar with Seattle, but your premise that the ridership figures are low-balled goes back to my initial concerns. How can this system possibly handle increased loads? LRT simply doesn't have that capacity with losing efficiency and rising per capita costs.

The 200 crush load for the train is non-sense. That's a vast overestimation. Studies show passengers WILL NOT tolerate loads like that as a routine. The 200 number is ridiculously high anyway. In Baltimore, the cars are 95 feet long, much wider, with 84 seats, and a crush load rating of 176.

Studies like those done at publictransit.us show that American ridership flattens between 90 and 100 for a 75-foot long Metro car, except where transportation conditions are extremely unfavorable otherwise (like NYC or Boston). Even in Chicago they rarely reach the estimated "crush". LRT tends to have lower loading tolerabilities than HRT, so for a (narrow) 95-foot LRT car, 120 people is probably the most reasonable routine rush-hour load to be expect. This is only about 60% of the idealized capacity of the system.

To reitterate (sorry): Knowing that LRT is difficult to operate below 5 minute headways without sacrificing reliability and/or speed, I don't see how this system won't either a) have ridership shortfalls, b) be overcapicity on day 1, or c) a combination of both. Everything says this line needs to be HRT to absorb long-term growth (if not immediately).

Thanks,
Nate
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Old March 4th, 2007, 02:09 AM   #370
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Quote:
Originally Posted by getontrac View Post
UrbanBen,

Thanks for filling in some more details.

I'm not that familiar with Seattle, but your premise that the ridership figures are low-balled goes back to my initial concerns. How can this system possibly handle increased loads? LRT simply doesn't have that capacity with losing efficiency and rising per capita costs.

The 200 crush load for the train is non-sense. That's a vast overestimation. Studies show passengers WILL NOT tolerate loads like that as a routine. The 200 number is ridiculously high anyway. In Baltimore, the cars are 95 feet long, much wider, with 84 seats, and a crush load rating of 176.

Studies like those done at publictransit.us show that American ridership flattens between 90 and 100 for a 75-foot long Metro car, except where transportation conditions are extremely unfavorable otherwise (like NYC or Boston). Even in Chicago they rarely reach the estimated "crush". LRT tends to have lower loading tolerabilities than HRT, so for a (narrow) 95-foot LRT car, 120 people is probably the most reasonable routine rush-hour load to be expect. This is only about 60% of the idealized capacity of the system.

To reitterate (sorry): Knowing that LRT is difficult to operate below 5 minute headways without sacrificing reliability and/or speed, I don't see how this system won't either a) have ridership shortfalls, b) be overcapicity on day 1, or c) a combination of both. Everything says this line needs to be HRT to absorb long-term growth (if not immediately).

Thanks,
Nate
theyre not expecting 200 people on each car... thats just the absolute maximum each car can hold...
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Old March 4th, 2007, 03:37 AM   #371
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Originally Posted by getontrac View Post

The 200 crush load for the train is non-sense. That's a vast overestimation. Studies show passengers WILL NOT tolerate loads like that as a routine. The 200 number is ridiculously high anyway. In Baltimore, the cars are 95 feet long, much wider, with 84 seats, and a crush load rating of 176.
Actually, 200 is about right for a car its size. Bombardier's site claims the minneapolis cars (same size as Seattle's) can fit 246. It's a combo of how many seats and how many standees / meter2 you use. Minneapolis has 66 seats and uses 6pax/m2. Seattle has 74 seats and uses 5pax/m2. Baltimore has more seats, and if you take out 8 of them, you'll have 200 capacity too. Some cities in Europe use 8pax/m2 to calculate crush loads.
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Old March 4th, 2007, 03:47 AM   #372
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Quote:
Originally Posted by getontrac View Post
To reitterate (sorry): Knowing that LRT is difficult to operate below 5 minute headways without sacrificing reliability and/or speed, I don't see how this system won't either a) have ridership shortfalls, b) be overcapicity on day 1, or c) a combination of both. Everything says this line needs to be HRT to absorb long-term growth (if not immediately).

Thanks,
Nate
We're currently building probably the least-projected-ridership part of our system right now (seems backwards to me). So yeah, in my opinion, on day 1, it'll be under capacity. The only crush loads seattle will experience are from stadium games, and maybe after the extension to northgate. But crushloads there should disappear if frequencies are changed from 6 minutes to 3 minutes since that portion is grade-separated.
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Old March 4th, 2007, 04:16 AM   #373
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Originally Posted by UrbanBen View Post
Haha! Glad I've allayed your fears.

At build-out (according to the '05 long range plan), you'll be able to board three kinds of trains at Everett, southbound: Tacoma trains (via SeaTac) every 5 minutes, Redmond trains (via Bellevue) every 7 (maybe 7.5?) minutes, and Issaquah trains (that hit Mercer Island and Eastgate) every 15 minutes. Combined, this gives you a little over 2 minutes.

I believe you're right that buses will be kicked out of the tunnel as headways decrease - I've heard that from more than one person. At that point, I should hope to see 3rd Avenue closed to cars entirely, but that's just me.
I think I just read the most recent plan (dec 06)...and Everett wasn't involved. It only went up to Lynnwood. Redmond has 1st priority for lightrail and Everett is 2nd, while Issaquah and Redmond via 520 are being studied for "high-capacity transit".

There are 3 lines:
1. Northgate - Port of Tacoma:...........4 car-trains 10mn peak; 15 offpeak
2. Lynnwood - Overlake via Bellevue:..4 car-trains 6mn peak; 15 offpeak
3. Lynnwood - Kent-Des Moines Rd:.....3 car-trains 15mn day; 20 night

So the northgate - downtown segment will have about 3 minute headways peak combined while offpeak will have about 5 minute headways!

I found it on one of their December reports online.

i made a simple map that shows the breakdown of the 3 lines with some stops. Of course this is waaay into the future and most likely will change.


Last edited by kub86; March 4th, 2007 at 06:34 PM. Reason: mapp
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Old March 4th, 2007, 06:13 PM   #374
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Quote:
Originally Posted by kub86 View Post
I think I just read the most recent plan (dec 06)...and Everett wasn't involved. It only went up to Lynnwood. Redmond has 1st priority for lightrail and Everett is 2nd, while Issaquah and Redmond via 520 are being studied for "high-capacity transit".

There are 3 lines:
1. Northgate - Port of Tacoma:...........4 car-trains 10mn peak; 15 offpeak
2. Lynnwood - Overlake via Bellevue:..4 car-trains 6mn peak; 15 offpeak
3. Lynnwood - Kent-Des Moines Rd:.....3 car-trains 15mn day; 20 night

So the northgate - downtown segment will have about 3 minute headways peak combined while offpeak will have about 5 minute headways!

I found it on one of their December reports online.

i made a simple map that shows the breakdown of the 3 lines with some stops. Of course this is waaay into the future and most likely will change.


Thanks for the map! This is consistent with my understanding for the lines that are being considered for funding under the regional roads and transit ballot measure that is to be on the ballot in November. Extending the system to Everett and Issaquah has been discussed but is not on the immediate planning horizon.

The mix of train headways results in a total of 20 trains per hour through central Seattle, which should be readily feasible. An important factor impacting the minimum headways between trains is the amount of time required to reverse a train. A four-car Central Link train will be about 360 feet in length. At a steady 3 mph walking speed, it will require the driver about one minute and twenty seconds just to walk the length of the train. This leaves little time for other actions that are necessary to reverse a train. I see this issue presently being agonized over in Los Angeles where trains will have to reverse out of Metro Center station every two and a half minutes once the Blue Line and Expo Lines are both at capacity. There are some things that can be done to gain more time for train reversals. One option is to have the trains alternate tracks so that a train arrives on the right-hand track and the next train arrives on the left-hand track while the first train is being reversed. This approach makes a lot of sense as long as the station has a central platform between the tracks. Another option is to have one more driver than the number of trains so that a driver walks the length of the platform while a driver from the previous train reverses his train out of the station.

A more complicated issue is how to reverse a train mid-route as will be necessary at Northgate. The Metro in Washington, DC has a third set of tracks at some stations specifically for this purpose. Perhaps Sound Transit is planning to do something similar at Northgate.

The reversal of trains is one area where fully automated systems such as Vancouver Skytrain have a major advantage. Such systems can achieve headways of 90 seconds or even shorter in some cases.
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Old March 4th, 2007, 06:46 PM   #375
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Originally Posted by greg_christine View Post
Thanks for the map! Extending the system to Everett and Issaquah has been discussed but is not on the immediate planning horizon.

A more complicated issue is how to reverse a train mid-route as will be necessary at Northgate. The Metro in Washington, DC has a third set of tracks at some stations specifically for this purpose. Perhaps Sound Transit is planning to do something similar at Northgate.

The reversal of trains is one area where fully automated systems such as Vancouver Skytrain have a major advantage. Such systems can achieve headways of 90 seconds or even shorter in some cases.
I just updated my map right after you posted. Anyway, what about a stub tunnel? Is that the 3rd rail you're talking about? That's what they're doing in downtown for reversing (which will probably be unused once north link is built). That's probably what they'll do for northgate.
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Old March 5th, 2007, 01:45 AM   #376
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Quote:
Originally Posted by kub86 View Post
I just updated my map right after you posted. Anyway, what about a stub tunnel? Is that the 3rd rail you're talking about? That's what they're doing in downtown for reversing (which will probably be unused once north link is built). That's probably what they'll do for northgate.
My guess is that the procedure for reversing trains in the rebuilt transit tunnel will be to first deposit passengers at the northbound platform, then proceed into the stub tunnel where the train will cross over onto the opposite track, and then proceed back into the station to pick up passengers at the southbound platform. My understanding is that the stub tunnel will eventually be part of the line to the University of Washington and points north.

On the Washington Metro, there actually is a third set of tracks at the stations that are used to reverse trains at intermediate points along the line. The following photo shows a train on the reversing track at the Silver Spring Metro Station on the Red Line:



Similar reversing tracks exist at Grosvenor Station on the Red Line and Fort Totten Station on the Green/Yellow Line. At both of those stations, the reversing tracks are in tunnels and are not readily visible from the platforms. There may be other stations on the Washington Metro that also have reversing tracks.
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Old March 5th, 2007, 08:04 PM   #377
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I've seen a method used where a cross over track exists just before the end station so that trains can alternate which side of the platform they stop at. Once underway, they'll use the same cross over in order to put themselves on the correct set of tracks.

This is a new construction photo of the station at International Blvd in Tukwilla. It has nothing to do with what we're talking about, but I just thought I'd add it in.



As for your request for more information about the problems in Portland, UrbanBen, I'll have to find specific information. I'm only generally aware that there were delays due to unforseen soil conditions. Again, specifics will need further research, but I should be able to search around for it. If I can't find it on the web, I'll be in Portland in a few weeks and can surely poke around in person.
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Old March 6th, 2007, 04:43 AM   #378
UrbanBen
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UrbanBen,

Thanks for filling in some more details.

I'm not that familiar with Seattle, but your premise that the ridership figures are low-balled goes back to my initial concerns. How can this system possibly handle increased loads? LRT simply doesn't have that capacity with losing efficiency and rising per capita costs.

The 200 crush load for the train is non-sense. That's a vast overestimation. Studies show passengers WILL NOT tolerate loads like that as a routine. The 200 number is ridiculously high anyway. In Baltimore, the cars are 95 feet long, much wider, with 84 seats, and a crush load rating of 176.

Studies like those done at publictransit.us show that American ridership flattens between 90 and 100 for a 75-foot long Metro car, except where transportation conditions are extremely unfavorable otherwise (like NYC or Boston). Even in Chicago they rarely reach the estimated "crush". LRT tends to have lower loading tolerabilities than HRT, so for a (narrow) 95-foot LRT car, 120 people is probably the most reasonable routine rush-hour load to be expect. This is only about 60% of the idealized capacity of the system.

To reitterate (sorry): Knowing that LRT is difficult to operate below 5 minute headways without sacrificing reliability and/or speed, I don't see how this system won't either a) have ridership shortfalls, b) be overcapicity on day 1, or c) a combination of both. Everything says this line needs to be HRT to absorb long-term growth (if not immediately).

Thanks,
Nate
Actually, 200 is the "routine" crush load. The absolute crush load of the vehicles was quoted to me today as 280.
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Old March 6th, 2007, 04:45 AM   #379
UrbanBen
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Quote:
Originally Posted by greg_christine View Post
My guess is that the procedure for reversing trains in the rebuilt transit tunnel will be to first deposit passengers at the northbound platform, then proceed into the stub tunnel where the train will cross over onto the opposite track, and then proceed back into the station to pick up passengers at the southbound platform. My understanding is that the stub tunnel will eventually be part of the line to the University of Washington and points north.

On the Washington Metro, there actually is a third set of tracks at the stations that are used to reverse trains at intermediate points along the line. The following photo shows a train on the reversing track at the Silver Spring Metro Station on the Red Line:



Similar reversing tracks exist at Grosvenor Station on the Red Line and Fort Totten Station on the Green/Yellow Line. At both of those stations, the reversing tracks are in tunnels and are not readily visible from the platforms. There may be other stations on the Washington Metro that also have reversing tracks.
There are, in fact, a few of these third tracks along the system. There's one in SoDo, and one in the south Rainier Valley, just that I've seen built. I believe there's room for another in the northern Rainier Valley.
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Old March 6th, 2007, 04:51 AM   #380
UrbanBen
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Originally Posted by getontrac View Post
UrbanBen,

Thanks for filling in some more details.

I'm not that familiar with Seattle, but your premise that the ridership figures are low-balled goes back to my initial concerns. How can this system possibly handle increased loads? LRT simply doesn't have that capacity with losing efficiency and rising per capita costs.

The 200 crush load for the train is non-sense. That's a vast overestimation. Studies show passengers WILL NOT tolerate loads like that as a routine. The 200 number is ridiculously high anyway. In Baltimore, the cars are 95 feet long, much wider, with 84 seats, and a crush load rating of 176.

Studies like those done at publictransit.us show that American ridership flattens between 90 and 100 for a 75-foot long Metro car, except where transportation conditions are extremely unfavorable otherwise (like NYC or Boston). Even in Chicago they rarely reach the estimated "crush". LRT tends to have lower loading tolerabilities than HRT, so for a (narrow) 95-foot LRT car, 120 people is probably the most reasonable routine rush-hour load to be expect. This is only about 60% of the idealized capacity of the system.

To reitterate (sorry): Knowing that LRT is difficult to operate below 5 minute headways without sacrificing reliability and/or speed, I don't see how this system won't either a) have ridership shortfalls, b) be overcapicity on day 1, or c) a combination of both. Everything says this line needs to be HRT to absorb long-term growth (if not immediately).

Thanks,
Nate
You know, let me address something here. We'll be operating our system at a minimum headway of 2.4 minutes upon buildout, when you start to see these loads. I'm not sure where you're getting some kind of inherent difference between LRT and HRT in minimum headway - is it possible you're confusing the term "LRT" with the definition "not grade separated"? The highest capacity portions of Link will be entirely grade separated.

How are you differentiating LRT and HRT, other than strict passenger capacity and overhead wire versus third rail (which is the most common distinction I'm aware of).
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