Green Line / Central Corridor construction thread (archive)

[FISHMANPET]

I have it on good authority from one of the SRF consultants who worked on Hiawatha that the power system can handle 3 car trains at 5 minute intervals.

[talindsay]

Yeah, 3 cars is the limit because of block sizing.

More specifically, the shared segment in downtown Minneapolis can't handle trains longer than 3 cars so our entire system is limited to 3 cars until that is addressed.

Realistically though, this brings up something I was thinking about last time I was in Paris. LRVs are *much* longer than traditional subway cars, such that a 3-car train is nearly as long as the subway trains in major cities. Ignoring special cases (such as the RER in Paris), metro systems generally max out at 7 subway cars, which are not as long as a four-car light rail train.

I don't think a city with our density is likely to ever need four-car trains; they'll just need to increase the frequency of three-car trains. At five minute headways, the capacity of three-car trains is quite impressive. Of course, at the point both the blue and green lines reach five-minute headways the need for a downtown tunnel will be due to traffic congestion, not platform length. But when that tunnel is built I suspect they'll choose to make the platforms long enough for four-car trains anyway, since there's no good reason not to at that point. I bet there are no constraints on train length on the Blue Line south of downtown; both the Terminal 1 tunnel station and the Lake Street Bridge station should already be long enough to accommodate 4-car trains, I think, and all the others could be expanded.

The Green Line will certainly never be able to accommodate four-car trains though.

[mattaudio]

Of course the Downtown Mpls interlockings and shared alignment with the Blue Line will be the choke point to preclude that level of service. Which is why it seems so strange that single tracking was summarily dismissed for the Green Line extension through Kenilworth (even though the LOS used to dismiss it would not be feasible without a new downtown alignment).

[FISHMANPET]

Maybe it was here or from the SRF guy (who taught a transit class at the U) that I heard it, but I think 2.5 minute headways is the limit downtown on surface streets because of the lights.

[mulad]

Yeah, we've rambled on about that before -- the cycle rate of traffic lights is a major limiting factor. Right now, with Target Field under construction, the crossover on 5th Street between Nicollet and Henenpin also needs to remain clear, so trains can't follow each other too closely. But once the Target Field expansion is done, that will be less of an issue. It would still be undesirable to have trains run more frequently than the timing to get from one station to the next, in case something happens and people need to be let off, but there are services in some parts of the world that can have multiple trains "in flight" between stations.

I've seen people worry about trains on 5th Street increasing congestion for cross traffic, or even parallel traffic, but I don't know how that's really possible -- the trains simply follow the traffic light cycle. There are some times when trains go through lights that they probably shouldn't (meaning the tail end of a train is still in an intersection as the cross light turns green). Metro Transit should probably be a bit more strict about that, though by the same token, there should be some signal optimization to make sure the trains (as well as pedestrians) aren't sitting there waiting when nothing is coming.

So if someone is bored enough, head into downtown and do some stopwatch timings of the lights along the 5th Street corridor.

[mattaudio]

It must be part of MetroTransit training for bus drivers too... It's nearly every day that I see a light turn green above the tail end of a crossing bus. Not that I blame them for getting transit customers down the corridor faster.

[FISHMANPET]

I did a ride along with a friend who was a driver (for an art class, I should put that video on YouTube...) and he actually brought up running lights. They're not "supposed" to run yellow and red lights, but they do anyway.

[RailBaronYarr]

It must be part of MetroTransit training for bus drivers too... It's nearly every day that I see a light turn green above the tail end of a crossing bus. Not that I blame them for getting transit customers down the corridor faster.

Yeah, on the flip side I've seen buses stop at near-side stops when the light is still green, only to have the light turn red on it while passengers board. Part of this is long boarding time with no pre-payment/etc, but on those stops, they typically sit for an additional 10-15 seconds with the intersection mostly to fully empty.

[mulad]

Fortunately for the Central Corridor portion of the Green Line, many stops are on the far sides of intersections, so that particular problem shouldn't happen as much.

[Silophant]

Uh oh. Looks like it won't delay opening, and the contractor's paying for it, so I guess it's not too bad. Sucks for the businesses, though.

[mamundsen]

Thanks!! I saw a sign on Lexington saying there would be road work soon near University. I was wondering what they would be doing SO soon after the Green Line project.

[mulad]

I took a ride on the 50 after work yesterday, and noticed a few spots where they were doing this work. I figured it would be right next to the tracks, but it seems to cover any place in the intersection where there is cracking. At Lexington, for example, there was a crack marked that extended from the outer lane of University Avenue through and beyond the pedestrian crossing that parallels University. It's certainly possible that concrete around the tracks themselves will need to be ripped up somewhere, but this should probably be viewed as a road repair problem rather than something specific to LRT.

[eazydp]

While riding a bus early this evening I saw three cars drive the entirety of the WATM. Two of which nearly collided with my bus when pulling from the tracks back to the lane and again when our bus pulled out from the station. For future reference, it was a rain/sleet mix during the drive time.

First off, the do not enter sign is hard to see. We all saw the pictures of the BMW which swerved onto the parked car at Appleby's due to that issue. The short term solution has been randomly stationing a metro transit police car just after the WATM lane becomes bike only. Secondly, why even make it possible for cars to continue driving. Is there a reason we cannot put a diverter in place? This problem is dangerous and needs a solution. What else could be done? Who can I/we contact to facilitate change?

[Silophant]

Well, keep in mind that that lane is a bike/emergency vehicle lane, so any diverter needs to still be passable to an ambulance or fire truck. I do agree that they could/should have made the outer lane out of pavers, or at least concrete, so it doesn't look exactly like a road. It wouldn't need to be particularly hard-wearing, since it won't get used by anything heavier than a bike very often. As to what will happen? Probably a bigger Do Not Enter sign. Maybe talk to someone at the U Transportation and Public Safety department?

[FISHMANPET]

Today saw a minivan going West on the transit mall, ending up behind a cop car stopped at the stop light at Church St. I figured the cop would get out and tell the driver to gtfo the mall, but it was raining and maybe the cop assumed the minivan driver was on his way out anyway.

The light changes and the minivan makes a U turn and goes back down the transit mall in the other direction.

[seanrichardryan]

Ruh roh- http://www.startribune.com/local/stpaul/255736521.html

I get it. My kitchen cupboards shake and my floors vibrate every time a truck travels down Hennepin or air-brakes heading into the tunnel. We are in one of the worst pothole seasons on record.

[David Greene]

Sweet Jesus.

http://www.startribune.com/local/stpaul/255736521.html

I am so glad I stopped giving money to that organization.

EDIT: Ah, beat to the punch.

Kerri Miller is the worst. There, I said it.

[mulad]

Cedar Street is rather bumpy along that stretch, despite being fresh concrete (it's only been open to traffic for about 12-14 months). I get bounced around a fair amount as I take the route 3 in each morning. It's better than Rice Street, but that's not saying much.

No big surprise that the train itself doesn't cause much trouble. I guess I never thought about crossings, though. Sometime last year, they did tear up a thin layer of concrete between each set of tracks for the crossing at 7th Street and then tack down some rubber pads. I guess that's not enough. I've been a little worried about the way these crossings were constructed, though -- I remember when the Snelling Avenue crossing first opened up, and some semi trailers (particularly empty containers on flatbeds) made horrific noises going over those tracks. It seems like some intersections have a concave surface between the tracks -- a feature that makes some sense for drainage along the line between intersections, but not in the intersections themselves.

The pavement seems to be flatter at intersections along the Blue Line, but I may be misremembering...

I may as well say that I'm also still worried about the crossovers by TPT and probably others along the route -- it doesn't really look like they've got a good way to cover up the switch equipment there (which had been damaged one night when a drunk driver went down the tracks and in the wrong direction on 4th Street). Hopefully they actually have something in the pipeline, because that one took forever to install in the first place, and it wouldn't be good if they had to make changes.

[David Greene]

No big surprise that the train itself doesn't cause much trouble. I guess I never thought about crossings, though.

I have it on good authority that MPR didn't either. The agreement was for Metro Transit to mitigate the *train* noise, not general traffic noise. Apparently Metro Transit is doing extra work to be a good partner. Wish the same could be said for MPR.

[mulad]

Hmm. The configuration at 7th got inverted in my mind. This is what it looks like. Three lanes of 7th Street have the treatment, but the travel lane farthest from MPR and some more space used for a service drive doesn't have the padding: