The High Level Bridge was used by the CPR up until 1989, and in 1994 they ended up selling it to the City. However, the way I understand it is that when the CPR offloaded it they gave the right of way atop the bridge to the Province — who as far as I know — still retain it for a probably not going to happen high speed rail line. My personal speculation is that given the recent structural studies on the bridge, and it being unable to serve as an LRT crossing, the Province might just end up dumping its claim to the top if the City comes up with some use for it.
What makes the High Level’s case particularly interesting though is that bylaw stipulates it can’t be demolished. When it was designated a Municipal Historic Resource in 1995 by the City they forfeited its right to do that. Now obviously there are different structural and safety requirements for bridges than there are for buildings, and changes will need to be made to it to keep it safe, but it’s something that has to be taken into consideration. If the City were to demolish it and void the MHR designation, then it basically nullifies the whole program and the legal protection that's enshrined within it for historic sites, opening the floodgates for any private landowners to do the same.
Personally, if possible, I’d just like to see the City find out what girders and joints are in especially rough condition, and just simply replace as needed with new ones. But who knows what kind of cost that would entail.