I have a several armored jackets from my motorcycling days. If you go down at 60 mph and slide off the roadway into a field, you'd probably do OK with one. If you were run over by a truck, it wouldn't really matter. It's really for abrasion protection, not impact protection. I guess motorcycle-style armor could help to some degree, but I don't think it makes sense for commuting unless you fall a lot.