Quote:
Originally Posted by UofC.engineer
Ok, the criticisms are valid then.
This sounds like a ridiculous question, but at what point is grade separation on a cross road required on an LRT system? Obviously there is different types of LRT technologies and different types of roadways. But is there a 'magic' number that planners use? (30,000+ vehicles a day)
I think Heritage Drive and 162 ave should have grade separation on the south line.
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Calgary's highest daily traffic volumes with at-grade crossings outside of the downtown are:
162nd Ave S - 25000
32nd Ave NE - 21000
Heritage Dr - 20000
58 Ave S - 18000
Saddletowne Circle NE - 16000
25th Ave S - 11000
(Macleod / 1st St E are 32000 / 28000 across 7th Ave, and are 25000/26000 at 10th Ave if the Green Line crosses them at grade there)
In Edmonton, the highest volumes with at-grade crossing not on the Metro line is at University Drive / 82nd Ave - 21000 which I understand is already a bit of a cluster due to the high volumes on the other side of the intersection and the turning movements. The other high volume crossings are 82nd st and 112 Ave by Commonwealth (18500 each).
But the Metro line north of downtown is ridiculous - it first crosses 107 Ave (18800 vehicles), then crosses Kingsway (16300 vehicles), then immediately crosses 111 Ave (23900 vehicles). Then, one stop later, it crosses both 106 St (4000) and Princess Elizabeth Ave (30000 vehicles). This is the really brutal decision.
Here's a link; look at it with your own eyes. In Calgary, the high volume roads crossed by the LRT have two things in common; first, they are nowhere near each other, so any delay is localized. The four main roads crossed by the Metro line are all within 2km of each other, and together they comprise the only four major east-west roads between 104th (the middle of downtown) and the Yellowhead, 4 km to the north (because of the airport lands).
Secondly, in Calgary the high volume road crossings are all (162nd aside) the minor road at/near their intersections, so the LRT can cross the road while a road parallel to the LRT has green time that it would have anyway. Sure, 25th Ave (for example) is stopped when the LRT is there, but it will always have a lot of red light time because Macleod is so much busier. At 106/Princess Elizabeth, the LRT crosses both streets so that the entire intersection is effectively shut down for the LRT. Not only that, but the LRT is negotiating a fairly tight (100m radius) curve and going immediately into a station, so the train will take a long time because of low speeds - in Calgary, the higher volume grade crossings (20K+) involve trains travelling straight track away from stations; even Heritage is actually 200m from the platform itself. The Kingsway crossing is in the middle of a block, so it adds a signal where there was none before.
The sad thing is, the Metro line came in under budget, by roughly enough to trench both the Kingsway and 106/Princess Elizabeth crossings. And all this, of course, leaves aside the signal debacle which is straight up incompetence as far as I can tell.
If the LRT is crossing a high volume road (and particularly a high volume road that isn't going to be grade separated in the future), the best practice is to do a traffic microsimulation to see what the effects are. I suspect that crossing multiple major roads in the same area produces more congestion than any single road crossing would.