As far as I know, most of this new extension is in underground subway - which makes it no example for the Ontario Line. If it was comparable, they'd have followed the existing railway alignment, that goes most of the way to Arbutus to Burrard and then elevated it down one of the laneways near West 4th.
Yeah, they looked at that - the problem with that alignment is it's at the bottom of a very steep hill for passengers to walk from 6th Ave up to the Broadway office buildings (9th Ave.)
and beyond to the hospital between 10th Ave. and 12th Ave. - ridership would have suffered significantly.
The Broadway Corridor has been studied for years, so the alignment was basically pre-determined.
The Broadway Extension (to Arbutus) is really Phase II West of the Millennium Line (Phase II East was the Evergreen Extension) - so it has been studied for close to 20 years.
The Millennium Line was built truncated, without either eastern or western extensions which would have supplied riders - think of it as our Sheppard Line.
The eastern extension (Evergreen Extension) was completed in 2016 and now the western extension (Broadway extension) is underway.
The further extension to UBC is relatively new and only on the table because of the growth in ridership on the rapid bus line, but the Broadway Extension will ease ridership with higher capacity through the Broadway office/hospital corridor,
so buses from Arbutus to UBC will in future largely carry UBC-bound passengers.
The main variable for the Broadway Extension was station placement - on which corner of the block.
... and no the public did not get to decide on the station sites because the sites were bought / negotiated in secret.
Mount Pleasant Station is across the street from the expected location.
Oak Station was moved a block east to be mid-block instead of on the corner of Oak - that placed it closer to the hospital.
Broadway City Hall Station will be a significant interchange station with lots of escalators and elevators linking platforms but no additional street entrances.
A plaza dedication (from a condo project) at Arbutus St. will be used for an emergency exit instead of an entrance, with the stationhouse across the street.
Broadway is like Bloor or Eglinton, so demand is on a relatively narrow corridor.