Protected lanes set up cyclists to get t-boned by turning drivers. In the US these are effectively glorified sidewalks where every road and driveway crossing is a death trap.
NACTO standards for protected intersections provide insufficient visibility for the cyclist and motorist on approach to the intersection [1]. For example they claim that for 25 mph traffic, the total clear sight distance should be 50 feet for a cyclist approaching the intersection where the turning car is ahead of the cyclist.
They're making several assumptions:
1. The cyclist will be looking to their left for traffic to the front rather than paying attention to what's directly in front of them
2. The cyclist assumes that the motorist cannot see them and will not yield
For the first item, there may be slower traffic in front of them they need to watch out for, taking their attention away from the street beside them. Same thing for surface hazards. For the second item, the cyclist may believe that since they can see the motorist, the motorist can see them and they can go ahead and proceed through the intersection.
From the motorist point of view, they're assuming that the motorist is lookinat the bikeway rather than at the road (checking the color of the traffic light, verifying that a car making a left turn is going to yield, pedestrians, etc). A motorist traveling between 15 to 25 mph is going to cover the clear sight distance of 50 feet in a second or two, meaning they don't have much time at all to assess the situation on the bikeway.
The second thing they claim [2] is that a bikeway setback increases visibility. Yet the pictures they use at the bottom of the page are the same picture cropped differently. One would think that they would have tried to use an actual example of this in their guide, but they did not. The other fundamental problem is that cyclists move between 15 to 30 feet per second. That means that a car driver needs to be able to see 30 to 60 feet down the bikeway in order to see an approaching cyclist in order to have enough time to yield to them. And they need to do this while moving through the turn at 10 to 15 feet per second.