I'm not worried about sexual predator abduction, except deep into the dark nights when I awake to a strange noise. It's at those times that I'm so glad to have my ferocious Bichon sleeping soundly at the side of the bed. If he's not worried, why should I be?
I do remember a welcome meeting to pre-school or early childhood family education where parents were advised not to leave brothers or sisters in the car when dropping kids off "for the obvious reasons". The "obvious reasons" were never stated, nor were they obvious to me. The likelihood of a stranger abducting my child from my car in the 5 minutes it takes me to walk her younger sister into pre-school is almost as remote as my chance of winning the lottery (which I refuse to play on arithmetic ground).
No. We should not fear predators swooping down and grabbing our children. There's a far greater danger that my 40 pound first grader would give herself a hernia walking the mile home from school on library day. I choose not to worry about that, either.
The more kids walking home from school, the safer all the kids are. The more parents who neighbors who volunteer as crossing guards, the safer all the kids are. The more exercise kids get, the healthier they will be.
In other words, walking is a big yes. Biking, for younger kids, remains a big no. For me, at least. A first grader on her bike is an accident waiting to happen. She's just learning to control her bike. She's distracted by friends. She's going faster than she ever has before and hasn't learned how far ahead she needs to look.
Let's face it. Kids aren't particularly bright creatures. Put them on bikes and many of them are going to pedal themselves directly into trouble.