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Post by Gokhan on May 24, 2011 7:36:28 GMT -8
Great videos, guys, thanks! They've left the third car at USC I guess for now.
After mid June or so, the signals, gates, and control systems should be finished and testing without flagsmen should be possible. It looks like testing so far has been very preliminary.
According to Expo finishing of testing by the contractor has been delayed for ten weeks because the contractor failed to obtain the necessary permits and make the plans. Contractor is blaming Expo as usual and asking for monetary compensation as usual. Expo thinks otherwise. They are trying to put the schedule back to normal though and it will have to be seen who will have to pay what and if the line still could open in November.
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Post by bluelineshawn on May 24, 2011 20:05:22 GMT -8
Thanks for the schedule update Gokhan. Hard for me to see how that type of delay could be Metro's fault.
The pedestrian looked a little confused in thanks4goingmetro's video. When a train pulls away from the platform and waits at the light, how will pedestrians know when to cross? There probably needs to be pedestrian signals on each side of the ROW, but it doesn't look like there are.
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Post by jamesinclair on May 24, 2011 20:56:37 GMT -8
Thanks for the schedule update Gokhan. Hard for me to see how that type of delay could be Metro's fault. The pedestrian looked a little confused in thanks4goingmetro's video. When a train pulls away from the platform and waits at the light, how will pedestrians know when to cross? There probably needs to be pedestrian signals on each side of the ROW, but it doesn't look like there are. It only takes one experience like that to make the person think "screw this, Im not going to wait here like an idiot". Same reason having pedestrian signals with broken timing leads to jaywalking. If someone stands there staring at a red hand, while parralel traffic has green, and knows they could have crossed safely within that time, next time around, they wont be waiting.
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Post by James Fujita on May 25, 2011 13:57:41 GMT -8
The video's subtitles says Crenshaw isn't going to be gated. I could be wrong, but it seems to me it really ought to be gated.
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Post by metrocenter on May 25, 2011 15:16:25 GMT -8
I can't imagine why Crenshaw/Expo is not gated. The crossing has both a major intersecting boulevard (Crenshaw) and a parallel street (Exposition). This makes it very similar to my home station, Wardlow, which is fully gated. The same thing applies to Crenshaw/WesternExposition.
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Post by James Fujita on May 25, 2011 16:30:19 GMT -8
When they put a light rail station at the corner of Crenshaw and Western, I would fully support gating the crossing. In fact, it may even need to be underground.
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Post by carter on May 25, 2011 16:36:38 GMT -8
When they put a light rail station at the corner of Crenshaw and Western, I would fully support gating the crossing. In fact, it may even need to be underground. Those two never intersect, do they.
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Post by James Fujita on May 25, 2011 16:48:27 GMT -8
seriously though, I would hope that the video was wrong. However, I don't see any crossing gates or signs that gates are ready to be installed.
Crenshaw/ Expo meets what I would consider to be standard requirements in that Crenshaw is a major street, and the Expo Line at that point stands on its own, separate from Exposition Boulevard.
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Post by bluelineshawn on May 25, 2011 18:06:15 GMT -8
I can't imagine why Crenshaw/Expo is not gated. The crossing has both a major intersecting boulevard (Crenshaw) and a parallel street (Exposition). This makes it very similar to my home station, Wardlow, which is fully gated. The same thing applies to Crenshaw/ WesternExposition. I don't know if Crenshaw needs gates for vehicles because the train stops in both directions, but it needs at least signals (if not gates) for pedestrians for sure.
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Post by James Fujita on May 25, 2011 18:11:35 GMT -8
I can't imagine why Crenshaw/Expo is not gated. The crossing has both a major intersecting boulevard (Crenshaw) and a parallel street (Exposition). This makes it very similar to my home station, Wardlow, which is fully gated. The same thing applies to Crenshaw/ WesternExposition. I don't know if Crenshaw needs gates for vehicles because the train stops in both directions, but it needs at least signals (if not gates) for pedestrians for sure. but if they had gates, would the trains have to stop in both directions? would they have to be as cautious as the trains in the video?
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Post by bluelineshawn on May 25, 2011 18:31:31 GMT -8
but if they had gates, would the trains have to stop in both directions? would they have to be as cautious as the trains in the video? Well yeah. The stations are right before the street. I was thinking that the train in the video was waiting for the flagmen. I doubt that will be the SOP once the line is in revenue service.
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Post by James Fujita on May 25, 2011 19:56:10 GMT -8
I hope that the signals are timed to match the trains, then.
Because really, when you get right down to it, the station platform isn't up against the street; you have a small, but noticeable buffer zone caused by the station entrance.
At other stations without signal synchronization, that has meant that the train pulls into the station, waits for passengers to get on or off, then pulls up a few feet to wait for the street lights.
And even then, the train operator has to be cautious for the late, last-minute light running driver, or other petroleum-fueled obstacles.
Any way you slice it, gates would still be better.
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Post by mattapoisett on May 25, 2011 22:40:28 GMT -8
but if they had gates, would the trains have to stop in both directions? would they have to be as cautious as the trains in the video? My theory is: If, God forbid, there is an accident or three, Metro may implement some strategy like what was created when the Orange Line buses kept on hitting cars when it first opened. Metro could make the trains creep until they are through the intersection.
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Post by Gokhan on May 25, 2011 23:06:44 GMT -8
The pedestrian looked a little confused in thanks4goingmetro's video. I liked that guy a lot. He was someone who wouldn't mess with a train for the life of it. If everyone were like him, there would have been absolutely zero pedestrian fatalities on the Blue Line.
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Post by thanks4goingmetro on May 25, 2011 23:52:40 GMT -8
The way the Expo train crosses these intersection is very similar to the Orange Line with the split platforms and signaling (no gates at Vermont, Western, Crenshaw), except at the intersections that have no stations it can blast by at 55 mph with the quad gates down.
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Post by thanks4goingmetro on May 25, 2011 23:59:47 GMT -8
but if they had gates, would the trains have to stop in both directions? would they have to be as cautious as the trains in the video? Well yeah. The stations are right before the street. I was thinking that the train in the video was waiting for the flagmen. I doubt that will be the SOP once the line is in revenue service. Yeah, the train could have crossed when it first pulled up to the intersection as all the cross traffic stopped, but it stayed there through a couple cycles of traffic (notice the flashing Train LEDs at the end of cycles) as they waited for the flagman to come (he even at the timing so he could just walk up when the cross traffic stopped). These crossings remind of the crossing gate-free Orange Line and Eastside Extension
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Post by metrocenter on May 26, 2011 8:28:29 GMT -8
When they put a light rail station at the corner of Crenshaw and Western, I would fully support gating the crossing. In fact, it may even need to be underground. Ha ha, I hope you all know what I meant (Western/Expo).
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Post by metrocenter on May 26, 2011 8:35:32 GMT -8
but if they had gates, would the trains have to stop in both directions? would they have to be as cautious as the trains in the video? Well yeah. The stations are right before the street. This is true for Crenshaw, but not for Western. At Western, the platforms are far-side, meaning all trains will stop at the platform after crossing the intersection. I don't recall seeing gates at Western, maybe someone can confirm. I think the crossing should be gated, since otherwise Metro may decide it has to creep its trains across the intersection every time. If that happens, it is going to be pretty frustrating for commuters.
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Post by carter on May 26, 2011 8:43:20 GMT -8
This is true for Crenshaw, but not for Western. At Western, the platforms are far-side, meaning all trains will stop at the platform after crossing the intersection. I don't recall seeing gates at Western, maybe someone can confirm. I think the crossing should be gated, since otherwise Metro may decide it has to creep its trains across the intersection every time. If that happens, it is going to be pretty frustrating for commuters. I don't recall seeing gates at Western at the press event a month or so back. I'm not even sure why you wouldn't have gates everywhere. Watching the Gold Line time-lapse video, you can see what a huge difference it makes. It's stop-and-go along the GLEE section and free sailing on the Pasadena segment.
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Post by thanks4goingmetro on May 26, 2011 21:05:50 GMT -8
I bike down Exposition Blvd almost daily, there's no gates at Crenshaw or Western. I read through the 2005 final EIR for the line and it has down the the Expo Line will use "the city traffic signals to cross the intersection." I think the split platforms will work well at Crenshaw because the crossing is after boarding but Western is totally backwards with having to cautiously cross or stop at the intersection then board passengers.
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Post by jamesinclair on May 26, 2011 23:02:50 GMT -8
I bike down Exposition Blvd almost daily, there's no gates at Crenshaw or Western. I read through the 2005 final EIR for the line and it has down the the Expo Line will use "the city traffic signals to cross the intersection." I think the split platforms will work well at Crenshaw because the crossing is after boarding but Western is totally backwards with having to cautiously cross or stop at the intersection then board passengers. No, you have it wrong. Far side boarding is almost always superior because it alows for signal preemption.
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Post by thanks4goingmetro on May 28, 2011 3:07:11 GMT -8
I bike down Exposition Blvd almost daily, there's no gates at Crenshaw or Western. I read through the 2005 final EIR for the line and it has down the the Expo Line will use "the city traffic signals to cross the intersection." I think the split platforms will work well at Crenshaw because the crossing is after boarding but Western is totally backwards with having to cautiously cross or stop at the intersection then board passengers. No, you have it wrong. Far side boarding is almost always superior because it alows for signal preemption. Sorry for stepping on your toes, dude, just speaking from my experience on the Orange Line with the split platforms.
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Post by bluelineshawn on May 30, 2011 10:44:43 GMT -8
From the May Transit Coalition Meeting the service level on Expo will initially be 5 tph (every 12 minutes) at rush hour which is pretty much what was expected. Brandon Farley also mentions that some Expo trains may depart 7th/metro as blue line trains which means that all rush hour Expo trains will be 3-cars. Also discussed is that the target date for opening is still officially November 15 although if it slips, it will slip to until after the holidays because opening during the holiday season presents several challenges. And if that happens instead of opening to La Cienega, they may look at opening all the way to Culver Junction which is currently scheduled to be ready for revenue service in March 2011. This is of course if La Cienega isn't delayed by that point. Let's cross our fingers for November!
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Post by bluelineshawn on May 30, 2011 18:22:15 GMT -8
Moved from the blue line threadFrom the May Transit Coalition Meeting the service level on the blue line will be reduced during rush hour from 11 tph (every 5-6 minutes) to 10 tph (every 6 minutes). This was pretty much expected so that service could be coordinated with Expo, which will run every 12 minutes. I don't see this as a significant issue for the blue line. The issue for the blue line at rush hour will continue to be that not all trains go to Long Beach making the Long Beach trains noticeably more crowded than the Willow trains. In other news a pedestrian was struck and killed at Artesia station. IIRC this is the third fatal accident at this station in the last few years. Maybe some safety enhancements are in order? Not sure because we never hear exactly what happened. Expo is only going to run every 12 minutes at rush hour? That's like local bus frequency. Geez. They didn't feel that they had much of a choice. They think that they have to run in some even multiple of blue line service so that boardings are kept level. I don't agree, but given that limitation they could only run every 6 minutes with shorter trains or every 12 minutes with longer trains. And they don't want to run frequent, shorter trains because for operational reasons they want to be able to use Expo trains as blue line trains and vice versa if one line or another has a problem. I don't know if they have enough equipment and doubt that ridership would come close to justifying 10 tph with 3-car consists.
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Post by metrocenter on May 31, 2011 6:52:46 GMT -8
I bike down Exposition Blvd almost daily, there's no gates at Crenshaw or Western. I read through the 2005 final EIR for the line and it has down the the Expo Line will use "the city traffic signals to cross the intersection." I think the split platforms will work well at Crenshaw because the crossing is after boarding but Western is totally backwards with having to cautiously cross or stop at the intersection then board passengers. No, you have it wrong. Far side boarding is almost always superior because it alows for signal preemption. I disagree. If signal preemption exists, far-side boarding and near-side boarding take equal amounts of time. In both cases, trains can enter and leave the station unimpeded. If signal preemption does not exist, near-side boarding is superior to far-side boarding. With near-side boarding, if a train hits a red light, the boarding and red light waits can overlap. While the train is waiting for the red light, it will already be boarding passengers - it won't be wasted time. Conversely, in the case of far-side boarding, if a train hits a red light, it has to wait twice (once at the light and once at the platform), and the time at the light is completely wasted. Here's an example. Let's say the signals are on a 40/40 cycle (40 seconds in each direction) and the train arrives at the crossing 20 seconds into a red light. Also, let's say boarding takes 30 seconds. - With far-side boarding, the train must wait 20 seconds until the green light, then cross, then board for 30 seconds. Total stall: 50 seconds.
- With near-side boarding, the train must also wait 20 seconds for the green light, but since it can begin boarding immediately, it only needs 10 more seconds to finish before leaving. Total stall: 30 seconds.
It is critical that signal preemption will be part of the operating plan for Western station.
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Post by Justin Walker on May 31, 2011 10:37:56 GMT -8
No, you have it wrong. Far side boarding is almost always superior because it alows for signal preemption. I disagree. If signal preemption exists, far-side boarding and near-side boarding take equal amounts of time. In both cases, trains can enter and leave the station unimpeded. If signal preemption does not exist, near-side boarding is superior to far-side boarding. With near-side boarding, if a train hits a red light, the boarding and red light waits can overlap. While the train is waiting for the red light, it will already be boarding passengers - it won't be wasted time. Conversely, in the case of far-side boarding, if a train hits a red light, it has to wait twice (once at the light and once at the platform), and the time at the light is completely wasted. As you note, the most desirable layout can depend on the level of signal priority. When preemption or high-level priority is provided, far-side stops are preferred because the intersection signal controller can easily determine when to give the approaching train a green signal. This is because the arrival time of a train approaching from a distance at speed can be easily calculated. For this reason, all of the stations on the Orange Line (except where prohibited by ROW constraints) feature far-side platforms. One Orange Line study notes "Traffic engineers also recommended far-side platforms wherever possible because it would be more difficult to pretime the following traffic signal with a near-side station dwell of unknown duration." The same study also notes that if very limited signal priority will be provided, great care should be taken to "to minimize the double-stop penalty of far-side stops."
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Post by jamesinclair on May 31, 2011 21:46:55 GMT -8
No, you have it wrong. Far side boarding is almost always superior because it alows for signal preemption. I disagree. If signal preemption exists, far-side boarding and near-side boarding take equal amounts of time. In both cases, trains can enter and leave the station unimpeded. If signal preemption does not exist, near-side boarding is superior to far-side boarding. With near-side boarding, if a train hits a red light, the boarding and red light waits can overlap. While the train is waiting for the red light, it will already be boarding passengers - it won't be wasted time. Conversely, in the case of far-side boarding, if a train hits a red light, it has to wait twice (once at the light and once at the platform), and the time at the light is completely wasted. Here's an example. Let's say the signals are on a 40/40 cycle (40 seconds in each direction) and the train arrives at the crossing 20 seconds into a red light. Also, let's say boarding takes 30 seconds. - With far-side boarding, the train must wait 20 seconds until the green light, then cross, then board for 30 seconds. Total stall: 50 seconds.
- With near-side boarding, the train must also wait 20 seconds for the green light, but since it can begin boarding immediately, it only needs 10 more seconds to finish before leaving. Total stall: 30 seconds.
It is critical that signal preemption will be part of the operating plan for Western station. I disagree. If signal premeption exists, the system operates better with far side boarding. Scenario: Far side, light is green: Train approaches intersection. Light stays green to let train pass and reach station. Train doesnt even slow down. Far side, light is red: Light changes to green after a brief delay, train slows and possibly stops. Near side preemption at station: Tran approaches intersection. Light stays green to let train pass. But wait, train needs to stop to allow passengers to board. :/ or Near side option 2: Train reaches station, boards. Train then needs to creep and come to a full stop forward to inform the light that it's ready to move. So in both near side scenarios, the train comes to a full stop. In far side, train does not. Your no signal preemption scenario is only 50% complete. Heres the other side: Here's an example. Let's say the signals are on a 40/40 cycle (40 seconds in each direction) and the train arrives at the crossing 20 seconds into a green light. Also, let's say boarding takes 30 seconds. - With far-side boarding, the train must wait 0 seconds until the green light, then cross, then board for 30 seconds. Total stall: 30 seconds.
- With near-side boarding, the train must wait 30 second for boarding, and then another 30 seconds for green light.
Total stall: 60 seconds.
And to combine those scenarios:
Far side: 30 + 50 = 80 Near side: 30 +60 = 90
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Post by metrocenter on May 31, 2011 22:56:28 GMT -8
[/li][li]With near-side boarding, the train must wait 30 second for boarding, and then another 30 seconds for green light. Total stall: 60 seconds. [/quote] What you're describing is a poorly-designed version of signal preemption, not any inherent flaw in near-side boarding. There is no reason whatsoever that the clock for the green light can't be triggered when the train stops for boarding. Boarding times are fairly predictable. In fact, this type of priority system is used at my home station, Wardlow station, for southbound trains (which board on the near side of the crossing). The signals and gates shut down the crossing at just the right time for the train to pull out of the station without any delay. Because the preemption system is properly designed, no trains experience any delays in either direction. Ultimately, my biggest concern about the far side platforms at Western is safety. With signal preemption, trains will be entering the crossing fairly fast. And unlike my Wardlow station, Western has no gates. I fear that this will result in accidents, followed by the inevitable calls for trains to slow to a crawl before crossing.
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Post by jamesinclair on Jun 1, 2011 0:46:57 GMT -8
Those examples were withOUT signal preemption. Anyway, we've talked many times about the extremely lengthy testing period the train must go through, and how it seems excessive because roads have zero testing period. Well, now I have an apples to apples comparison. Six Flags is building a new roller coaster. As of May 18, they were still installing track www.facebook.com/photo.php?fbid=10150250880892125&set=a.10150134721442125.325848.67502107124&type=1&theaterAs of May 31, they're still finishing installation, and the rail cars havent been installed on the track yet. The ride is scheduled to open on June 18. Now, Im no engineer, but it seems like a roller coaster is a more complicated piece of train infrastructure than a light rail line. So why are they ok with, what, 12 days of testing, while expo requires 5 months...? Why do the minimum wage train operators do fine with a week of training, while metro's professional train operations staff needs 5 months to figure out how to accelerate and brake trains theyve been driving for years?
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Post by transitfan on Jun 1, 2011 5:52:51 GMT -8
[/li][li]With near-side boarding, the train must wait 30 second for boarding, and then another 30 seconds for green light. Total stall: 60 seconds. [/quote] What you're describing is a poorly-designed version of signal preemption, not any inherent flaw in near-side boarding. There is no reason whatsoever that the clock for the green light can't be triggered when the train stops for boarding. Boarding times are fairly predictable. In fact, this type of priority system is used at my home station, Wardlow station, for southbound trains (which board on the near side of the crossing). The signals and gates shut down the crossing at just the right time for the train to pull out of the station without any delay. Because the preemption system is properly designed, no trains experience any delays in either direction. Ultimately, my biggest concern about the far side platforms at Western is safety. With signal preemption, trains will be entering the crossing fairly fast. And unlike my Wardlow station, Western has no gates. I fear that this will result in accidents, followed by the inevitable calls for trains to slow to a crawl before crossing. [/quote] Well, what is actually happening at Wardlow is that the Blue Line train operator is requesting the gates to be closed by pushing a button on the console once the train is berthed at the station. This happens at several points along the Blue Line private ROW, where the crossing gates are relatively close to the station platform, and therefore cannot be triggered automatically. The other places where this occurs (IIRC) is Washington (southbound), Compton (southbound), Imperial (northbound, although maybe not anymore since the Imperial Hwy grade separation), 103rd St (northbound), Florence (northbound), Vernon (northbound).
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