I'm glad you didn't get seriously injured, and sorry this happened to you. My wife was involved in an accident on a bike trail and suffered a concussion and short term (6 hours) memory loss/amnesia. At 10mph her helmet saved her life.

I never ride on a bike trail, too many idiots, kids, animals, etc...make it way too risky, I go out of my way to avoid them. My wife finally realizes it's much safe on the road.

I've also noticed that vintage steel bikes don't hold up well to crashes. 8mph? Carbon or aluminum bikes would certainly hold up.

You also need to re-think your route, your just asking for trouble riding over pedestrian bridges and sidewalks..Most of the time it's most safe to ride with traffic.