Instead, I'll say that just as people walking need physically protected infrastructure on essentially all roadways - these are called sidewalks - so too people on bicycles need physically protected infrastructure on essentially all roadways - these are called protected bike lanes, or cycle tracks, or various other names.
For some recent commentary on this topic from Boston, see the following. The first is from a columnist, and the second from the President of the Boston City Council:
https://www.bostonglobe.com/opinion/2016/08/12/bikes/yOFRBYH...
https://www.bostonglobe.com/opinion/2016/07/11/the-road-fear...