Green Line / Central Corridor construction thread (archive)

[Silophant]

I think there's a good chance they have, now that it looks like Spring might have finally arrived for real. Hopefully LRV Op Guy can tell us for sure.

[Suburban Outcast]

My guess is they are as well because when I went to an interview yesterday in downtown Saint Paul, I saw a train strolling down Cedar when I was on 7th. I got a bit excited once I realized it's getting closer to the opening date.

[eazydp]

Snapped a photo of a test train on the WATM at Walnut St yesterday.

[talindsay]

My phone was too slow loading the phone app to catch a picture of the test train that just whisked into the West Bank station. They appear to be operating at full revenue speed now, which isn't fast but it's quite a lot faster than I expected as they cross the bridge heading west. It'll be nice when they start running multi-car trains, we'll get a better sense of how it's really going to run.

[LRV Op Dude]

Pre-revenue service has not started. Some work still needs to be done. Trains are now running from West Bank to Union Depot thought out the day. When you see train running every ten minutes that is a good sign that Pre-revenue service has started.

[ProspectPete]

This morning I was in Lowertown and saw they were doing some LRV testing. One of the drivers happened into the coffee shop, and I cornered him and asked him about signal priority. Friendly guy who was more than happy to answer my questions. When I point blank asked him a yes no question as to signal priority, he kind of shrugged and said that they have to "work with traffic and work the city" since they won't have any stop arm gates like on Hiawatha, and that in the future they could maybe make some adjustments.The feeling I got from the conversation was that there really is no signal priority for the CC green line. This corresponds with what I've so far witnessed, as well as what someone who worked on the engineering of the project.
If that is the case, it will be a very, slow, train.

[Minnekid]

If there is no signal priority and the line is running mostly through developed corridors, I don't see it being much faster than a bus. It will also have irregular arrivals to stops. So either it must get signal priority or it will be a big bus.

[mattaudio]

Now just imagine how this would work with weak signal priority and no dedicated ROW (cough Nicollet Streetcar)

[exiled_antipodean]

I can understand why they might not have signal priority in this phase of testing, but banging my head against the wall if they don't have it for revenue service.

Saw two trains dwelling briefly at the Prospect Park station today. Might have to pay more attention to the traffic on 29th Avenue now than I used to ...

[tabletop]

It seems as though the timing of the lights is geared towards letting the trains through the intersections. I've noticed from driving down University that they are fairly competitive, as far as speed is concerned, with driving. You can catch up to a train if it's ahead of you, get in front of it, but it stays with you and passes if you need to take a left. A vast improvement over the bus.

[Mdcastle]

They will have priority but not preemption. Meaning that they're timing the lights to expedite LRT vehicles getting through, but a train will not have the ability to preempt a light- turn it green when it would not otherwise. It was tricky enough to get the lights on Hiawatha working decently for car traffic with preemption, and there's a lot more lights on University. In practice I assume it means a train may or may not hit the first red after leaving a station, but should have green lights thereafter.

[Suburban Outcast]

I hope the signal algorithms are set up better than Hiawatha because the lights are really odd at times when I've driven on it, and they seem to bunch up traffic unnecessarily. I remember spending a few minutes at the stoplight at 26th, and it stayed red for 5-10 minutes even though Hiawatha wasn't blocked by a passing train like 26th was. I just feel it would easier to let a green cycle to happen in between to let traffic flow better.

[web]

very different being in the middle of university most of the way!

[mulad]

The way signal priority has been described when talking about the enhanced bus (aBRT) lines in the area has been that a bus coming up on a signal can request it to stay green a bit longer.

Actual preemption seems a lot more difficult these days, especially with countdown timers on crosswalks -- it wouldn't be very good for that segment of time to suddenly be cut out, aside perhaps because of an emergency vehicle coming along.

Roughly half of the intersections along University Avenue have been closed to left turns and through traffic (for cross streets). Trains will typically only go through two intersections between each station, even though typical spacing is 4 blocks. They've limited the number of places where the trains may be forced to stop, though it's still many more intersections than there are along Hiawatha.

The signals along University are set up with a dedicated phase for left turns for traffic leaving University for cross streets. Trains should be able to go straight whenever the regular traffic lanes have a green light, though as we've observed, that doesn't always seem to match up (part of it can be explained by the need for trains to brake more slowly than cars).

I was amazed to learn how un-intelligent the traffic signals along Hiawatha were -- a train coming along would cause the signals to reset to the start of a pre-programmed cycle, rather than resuming where they left off after a train preemption ended. Supposedly they're smarter now, but I don't go over there often enough to tell the difference.

[Mdcastle]

For preemption it doesn't matter if there's a countdown timer or not- the only circumstances where you may terminate a pedestrian clearance phase early is for a freight railroad where the train cannot stop, and even there they're trying to eliminate this by putting advanced sensors on the railroad to prevent serving the pedestrian phase if there's not going to be enough time to complete it.

Hiawatha- This area tends to use Econolite controllers which I'm not that familiar with programming, but my own controller, the PEEK 3000, still doesn't have a firmware option to resume timing wherever it was when a preemption run expires- you have to set the phase to enter, not "resume last phase" or "go to what the next phase would have been", so it's believable that was simply not an option at the time.

[Silophant]

There's currently a train stopped at West Bank station that's 4 LRVs long. I believe the Blue Line maxes out at 3-vehicle trains, right? Is the Green Line actually going to run trains 4 vehicles long?

On another note, I just saw another train of the old LRVs with the new livery, but the old destination signs. Progress!

[Tom H.]

Judging by a 3-car train I saw running through campus a few weeks ago, I believe a 4-car train would be longer than most blocks along Washington/University. Correct me if I'm wrong, but I believe 3-car trains also completely fill up downtown blocks along 5th St as well.

[Silophant]

That's kinda what I was thinking, especially with the signaled midblock crossings on the transit mall.

[FISHMANPET]

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

[mulad]

I measured a couple of 3-car trains that show up on Google Maps, and they came out between 278 and 279 feet, so a shade under 93 feet per vehicle. The platforms (not including access ramps) tend to be about 10 feet shorter than the overall train length, since they only need to be long enough to cover all doors.

There is one small block at the Huron / University / Washington triangle that is too short for even 3-car trains, so they must have some special signal phasing set up there.

I would guess that this 4-car train is being used for some sort of electrical load testing, or maybe some weight testing for the Washington Avenue Bridge. They ran some 3-car trains on Hiawatha when it was in testing, in order to make sure it could handle higher-than-normal electrical loads. I believe they had two 3-car trains accelerating in opposite directions on the same section of overhead line for that test. I was surprised that Hiawatha has gotten some upgrades to its electrical system in recent years. I guess daily operation of 3-car trains still hadn't been anticipated even with those early tests.