Originally Posted by I-Like-To-Bike
Good point. Nor does Forester or any of his minions identify any characteristic that makes a cyclist "vehicular" when their claims are made about an alleged superior safety record for the mystery population of vehicular cyclists. The closest working definition for the proselytizers establishing a "safety record" appears to be that everybody is a "vehicular cyclist" until they have an accident, then they are not.
To the OP. The reference for the comparison of wildly mismatched populations of cyclists with scanty to non existent risk factors can be found in the other Forester tome,
Bicycle Transportation, 2nd Edition published by MIT Press in 1994. Chapter 5 I believe.