Originally Posted by
genec
The laws of physics alone make it safer to be on a bike path vice a roadway... getting hit with 3000 pounds of mass moving at 30 MPH will impart more force than being hit by 200 pounds of mass moving at 20 MPH.
You're forgetting their frequency and how to weight different injuries/mortality. "Safer" in a broader context probably includes things other than mortality; although it is harder to measure. If we really wanted to do a good job, we would consider rider selection. That is, what would happen if you took the road cyclist and put him/her on the MUP and vice versa.
Anyway, if all you care about is mortality, then avoiding cars is a simple but generally a very limiting way of doing it.