There is no need to make the lane wider. Any lane that can accommodate one motorcar can accommodate at least one or two bicycles.

In my years as a transportation planner, I have never even HEARD of a cyclist being run over by a motorcar driver directly from behind. Time and time again, I've read about right hooks and truck operators saying such things as "he came out of nowhere!" As a vulnerable cyclist, it makes NO SENSE to be off to the side, out of direct sight of a motorist. I want them to see me. These are basic traffic engineering concepts that I had learned at an early age in regards to motorized vehicles, and why they are seemingly NOT applied to non-motorized vehicles is a bit strange, to say the least.