Cars always win in collisions. With mobile phones it's not safe to train on open roads.Putting blame on the riders/teams for these incidents is not classy. Scarponi was killed at a junction in the town he lived in on a recovery ride. Froome was doing an obligatory TT course recon. They have no choice but to train on roads that they will encounter in races. Cycling is a skill based sport, not just physiological.
The only issue here is making young cyclists aware of the risks and understanding road safety, but primarily the issue is not the cyclists themselves but who they share the road with.