We are mostly in "violent agreement" as it is called. If you are on a separate / protected bike path (not on a road intended for cars), then there are no cars

We are mostly in "violent agreement" as it is called. If you are on a separate / protected bike path (not on a road intended for cars), then there are no cars there, nor can they easily get on that path. In practice such protections/barriers might range from moderately difficult to surmount (raised curbs ~ 50 km/h) ; nearly impossible to penetrate (row of trees, solid concrete wall, drainage ditch full of water ~ 80km/h); to outright having the bicycle path follow a different right of way altogether( >80 km/h ). In general, the routes for cars, bikes, and pedestrians should be separated wherever there are large differences in speed that can lead to danger. Edit: See also one of the sources for the video, eg. https://bmjopen.bmj.com/content/bmjopen/5/11/e008052.full.pdf https://bmjopen.bmj.com/content/bmjopen/5/11/e008052.full.pd... The conclusion is that wearing a helmet doesn't help as much as physically separating bicycles from other traffic. While it may be good to be protected in case of accident, it's much better to avoid having the accident altogether.