My husband used to ride bikes a lot, and when our son was born we were thinking about getting something along that line so he could ride with Mike...we ended up not getting anything because he didn't have time to ride anymore, but I digress....Anyway, from the research 12 years ago, the feeling was the trailer type carriers were much safer than the carriers that attached to the back or front of the bike because if the rider and the bike fall, the trailer stays upright and thus the child/pet is safe.