"Another study surveyed 2,400 cycle commuters in the US and Canada. The results provided the following “relative danger indices” for transportation infrastructure categorized in more detail than the Ontario studies: sidewalks = 5.30; major streets without bicycle facilities = 1.26; minor streets = 1.04; off-street bike paths = 0.67; streets with bike lanes or bike routes = 0.50 [
Moritz 1997]."
http://www.cher.ubc.ca/cyclingincities/injury.html