In my career, I've observed and studied several European-type separated bicycle facilities installed in the US and Canada. At each one, I have observed a number of conflicts between motor vehicle and bicycle traffic at intersections, where riders or drivers must stop or turn suddenly to avoid a collision. In locations where the built environment constrains maximum motor vehicle speeds to around 20-25 mph, there are many conflicts (almost one per signal cycle on some busy paths), but almost no reported collisions or injuries, as the traffic on two and four wheels swerve, brake, and yell a lot in the local profanity of choice (in Montreal, I'm sure most of the words I heard weren't in a French textbook). But the official records note very few of them are getting hurt. However, where such a facility is adjacent to and crosses roads with suburban-type speeds above 30-40 mph, some of the conflicts become severe or fatal angle crashes, as the driver no longer has as much time/distance to perceive and react. Signalization has been used to try to restrict bicycle and motor vehicle movements to phases with no conflicts, but many observed cyclists (especially in dense urban areas) enter or cross when they choose regardless of the signal display to reduce their overall delay. As an experiment on the Pennsylvania Avenue median cycling facility in NW DC, I strictly obeyed the bicycle signals from the Capitol to the White House. I was 15 minutes late for my meeting.