I think an LRT line should be buried or built above where there is high traffic or pedestrian activity (creating more congestion), or where there is an opportunity to create a new traffic route (like the Tawatina bridge or the proposed bridge over Yellowhead Trail and the Calder Yards.
Wait, so again, we're making transit more expensive to build, operate and maintain because we're giving priority to cars?
We're looking at the whole thing with an approach that doesn't make much sense, IMO. The whole idea of at grade, low-floor is that it's more dynamically integrated to the urban fabric and its no as expensive as full metro systems, being financially more interesting to "small" big cities, like Edmonton.
The costs of building an underground LRT line are, essentially, prohibitive is we want to build it all the way to some of the more distant suburbs and serve more os the city.
Also, not necessarily congestion is a bad thing, especially if we're talking downtown and TOD areas. We want this areas to be less aggressive for pedestrians, with lower speeds, etc. We want people to be able to see and identify storefronts from their cars (and from transit), which is particularly good for smaller local businesses which are not chains and depend more on visibility to keep their doors open.
We need to stop building out cities for cars, rather than for people and, with this in mind and given Edmonton's characteristics, I believe that the line being above ground is a good thing and has the potential for a really positive impact on the city.
As for the speed of the system, itself, as long as it has priority over cars, it will be relatively fast in the downtown core and, in the other areas, it's going to be even faster, as the stations are further away from each other and there's less intersections to be concerned with. By the way, if you notice, a lot of the stops are right at a traffic light, which is a very intelligent design idea, because it reduces the number of times the trains stops, if timed correctly.
Taking personal experience into account, Rio's downtown os much bigger, busier and complex than Edmonton's, due to it's historical characteristics and for being a heritage area. It's LRT covers, with 3 lines, 27km, one of them is fast enough to go from the intermunicipal bus station (which is a major transportation hub) to the downtown airport in less than 25 minutes, crossing the whole downtown area (which is roughly 3 times larger and A LOT denser than Edmonton's). The other two are, somewhat, circular lines within downtown, covering most of it, with stops within walking distance from the main roads, which improved the mobility in the area, boosted businesses in street that were "abandoned" and, overall, had a hugely positive impact in the city, much more than anticipated and, for the most part, even unexpectedly, given the degradation level of Rio's downtown. Now imagine if it had been planned with this whole urban development impacts in mind, how bigger the impact could've been?
Now, before any of you point out that the weather is somewhat "better" and that it's easier yo have at grade lines in such an environment, having lived there, I can assure you that it's no easier or healthier to wait for a train/bus with 40ºC (45~50 with humidex), under the sun, in the middle of a busy and heavily polluted area, than it is to do it with the extreme opposite here. Summer there lasts as long as winters here and, in some ways, it's even harder to endure and much more uncomfortable, for some people.