Back to Halifax, given the travel time savings predicted at peak:
We can see where the travel time savings are likely coming from.
All routes coming and going from Bridge Station have travel time savings, so I bet they're improving access to and from the station itself for ~ 1 minute of savings.
Both routes crossing the bridge have a savings, so improvements on the bridge itself likely contributes ~ 2 minutes of savings.
The purple bridge route going to the Shopping Centre has significant time savings. The purple route through the Robie/Young intersection is likely to be prioritized (perhaps an intersection skip), most likely with skips at Bayers/Oxford, Bayers/Windsor/Young too.
The further out sections, I bet they can get those travel time savings just from moving where stops are, having less stops, perhaps extending greens, shortening reds, and having a bit of preemption at stations.
All in all looks like a good plan - for only $132 million.