This always surprises me about my newly adopted country. A law that would guarantee to save lives is rejected because folks don't like the feeling of being told what to do. The term "nanny state" is bandied around.
If the life saving message isn't working, a better approach would be to set out the insurance premium savings perhaps. Or a video of a cycling accident where the victim is not wearing a helmet. That'd do it. Either which way I am amazed that the personal freedom message beats out the saving lives and saving money message. As it stands, natural selection will win the day.