I'll give you a hint about statistics... there will always be a #1 killer of children. Today it's car accidents, 100 years ago it was disease. After disease it was other accidents, and 100 years from now it will be something else.
Listen I agree with both you and the poster I replied to. What I am saying is that the risk from cars really did increase. Not that it's the only reason that the change happened.
I don't think you ever saw the cars my grandmother drove when my dad was a kid. It was not a "light truck" or anything of the type. It was a 'car' and it was actually bigger, by quite a large margin.