The zeal with which Americans have sought to impose laws that interfere with an individual's freedom of choice has never ceased to amaze me.
I personally wear my seat belt habitually and request my passengers to do the same. I do this because I value my own life and that of my friends and family. I also do this because I feel that it is foolish to do otherwise.
However, it is not the role of government to prevent its citizens from making foolish decisions unless those decisions infringe on the rights of others. A more sensible approach would be to reduce the limits of liability for a motorist who injures or kills someone who was not using a seat belt.
Seat-belt laws for children make sense because they are not capable of evaluating the consequences. Adults are, though, and should be allowed to make those decisions without the threat of government coercion. However annoying it may be to the rest of us, people have a right to be fools.