I don't know if anyone has seen this yet, but there was some research/advocacy group from the other side of Canada that actually conducted their own study of the technology choice for the Crosstown LRT and found the choice of LRT technology more expensive than a rebuild of the Scarborough RT to more modern standards and the building of the Crosstown LRT under the same (but since-improved) technology. Apparently it would've saved the same amount of money (that moving some of the LRT at-grade would have) or more to switch the technology choice, because of a specific in the diameter of the tunnels.
"The compromise is SkyTrain: Toronto should be pursuing this technology and not LRT on Eglinton" at SkyTrain for Surrey
Everything makes sense, and it looks like these guys do know their stuff.
I read the report, and have doubts about its credibility:
1) In the second paragraph, they make a frivolous claim that "The at-grade switch would have impacted the entire line’s operating speeds and add 20 minutes (a nearly 50% increase!) to the end-to-end trip travel time."
In reality, the central section is in the tunnel either way. The debatable section between Brentcliffe and Kennedy is 9 km long; will take about 23 min (at 23 kph) for surface alignment versus 16 min (at 34 kph) for tunnel or guideway. The difference is 7 min, not 20.
Even if we add the future section west of Jane, about 8 km to Hwy 27, the combined difference will be 13 - 14 min, not 20.
2) The statement that ART trains can run at 110 kph is irrelevant; streetcars can run at the same speed, and good old buses can run much faster on a highway. In the city conditions, the operation speed depends on the stop frequency and acceleration / decelaration; theoretical top speed has little effect.
3) Equally irrelevant are their statements about the 56,000+ pphpd capacity that both subways and ART can reach, based just on the train load and frequency. In reality, such volumes will hit other constraints: stairs, escalators, exits etc. Yonge subway line will undoubtfully choke if it tries to handle that kind of demand; no way an ART system with 80-m platforms will handle it.
4) Their claim of lower operating costs due to the driverless operation of a fully graded line does not account for the higher maintenance costs of fully graded stations.
Finally, they believe that the smaller tunnel diameter and hence the lower cost of the tunneled section can offset the cost of grade separation on other sections. That might be true, but they did not provide any cost estimates to support it.