Quote:
Originally Posted by lubicon
Outside of a few blocks downtown the Green Line will (unfortunately) be at grade most of its alignment. Is the comment about Calgary (and Edmonton) doing it backward really valid? When the initial lines were constructed in the 80's were there actually viable low floor alternatives for LRT? Honest question - I don't know.
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No, that's fair. The first completely low-floor tram was introduced in the '90s.
This guy:
https://en.wikipedia.org/wiki/ADtranz_low_floor_tram
That said, there were always partially low-floor or high-floor-with-steps trams. I kind of like San Francisco's Muni high-floor trams, which above ground feature a small, ramped platform for wheelchair accessibility, and stairs that raise themselves when the trams go into the downtown subway, for the sake of level boarding at platforms.
In the scheme of things, both Alberta LRT systems are really unconventional. Things like high platforms on a street, crossing arms on a tramline, and light-metro trains rolling down streets are really odd. Hence my reference to them as freight trains before.
Anyway, a lot of you are really wringing your hands about tramways, and it shows you don't have a lot of good experiences with them. I'm willing to bet that most of you have a bad taste in your mouth from the TTC's offering, or some of the borderline white elephants in American cities. I always thought Minneapolis's was kind of bad, even though it shares more in common with the C-train than a tramway.
But a well designed tramline is pretty quick.
A few keys to a good tram line:
1. Long blocks. milomilo mentioned this with respect to the C-Train. It's an intuitive point, but worth illustrating in contrast to what happens with TTC streetcars. They mostly run east-west, across the grain of the city's blocks. This increases potential points of conflict.
2. Keep stops at least 500m apart. There aren't many good excuses for spacing transit stops closer than this. Toronto's Spadina line is frustrating because its stops are 200m apart. The Minneapolis tram leaving mall of America manages to trundle around for almost a kilometer to end up at its first stop, 400m from where it started, then piles up three more stops over the next 900m.
What the hell? Obviously that's going to be slow. A grade-separated system that stopped this frequently would also be slow.
3. Get the signals right. The last time I was in Toronto I watched a St. Claire tram pointlessly wait for a left-turn signal. One car went through. Spock always did say, the needs of the many outweigh the needs, or wants, of the few. A tram carrying dozens of people should obviously have priority over cars that obviously aren't carrying dozens of people. And putting stops before lights allows cross traffic to move while the tram is stopped anyway. Good signals can make up a lot of the advantage of grade-separation. In the end, the point is to...
4. Keep cars away. A tram in its own ROW is best. A good ROW can be grade-separated, sure, but it doesn't have to be. It can run down a median, but it doesn't need to be down a median. It can run down one side of the street, or cut through parks, plazas, buildings. And a good tram line doesn't need an exclusive right of way, exclusively. Trams can run in mixed traffic without delays as long as they're given an out from mixed traffic before it can slow them down.
Here's an example from an outer district in Berlin:
https://www.google.com/maps/@52.5503...8i6656!5m1!1e2
This tram mostly runs in a median ROW. But for about 200m the street is too narrow to afford both directions an ROW. In this case, inbound trams get the ROW while outbound trams get mixed traffic. Why? Because the outbound trams are leaving a stop, at a traffic light. It's incredibly unlikely that traffic could hold them up; they're all moving at the same time and speed, and by the time traffic has to stop again, the tram is into its own ROW. The inbound tram, however, could get help up by traffic at the light, thus preventing it from getting to the station and the safety of its ROW. So it gets a single-lane ROW, allowing it to queue jump.
Here's another example from a more central part of Berlin:
https://www.google.com/maps/@52.5394...8i6656!5m1!1e2
Here, the tram runs in mixed traffic down a popular commercial high street. What you can't tell from this streetview, is that the end of this block, where you'll find the tram stop, is closed to cars. This prevents the street from becoming a thoroughfare, and keeps traffic light. Trams don't run at great speed down this stretch, but they run at a regular speed, and that keeps the system predictable and reliable.
If I had my druthers, the R in RT would always prioritize reliability over rapidity, and thereby actually realize rapidity. Poorly designed streetcar or bus systems aren't reliable, and end up bogged down in traffic--much like traffic itself. You'll find with at-grade tram systems that if traffic is light, they're slower than cars. And why wouldn't they be? They have to make stops that cars don't. But when traffic picks up, it slows down. That's when at-grade systems shine, because they runs at the same speed no matter what.
Another virtue of at-grade systems that people miss when they get worked up about point-to-point speed, is the speed of using the system. An at-grade tram is very accessible. Compared to grade-separated systems, it's much faster to get to the transit. The difference in Berlin, where the subways run just under the roads and don't have fare gates, isn't that pronounced. But somewhere like Kiev, where getting to the subway is a commute unto itself, you're often better off taking trams than joining the miners going to the subway.
Sprinting across town on a fast train is a lot less impressive when you tack on five minutes of escalator rides and waiting for people fumbling with their metro card at the ends.
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