i'm sorry for my last posts being off topic.

YES, narrow lane crashes do happen, helmie. proven and rare, because most cyclists move right in the face of overtaking traffic, even you. (not describing a 'narrow' lane there, just lane positioning as a general concept) and lanes are not always, often not always, strictly 'narrow' so as to be defined that way.

but cars get rearended, probably a LOT more likely than cyclists. how does a vehicle's mass and likelyhood of center of the road position modify the conspicuity variable?