In a free society, each person owns himself. As such, he has the broad discretion to make his own choices regardless of what others think of the wisdom of his choices. He has the right to take chances with his own health and safety. However, if an American doesn't own himself, and it's Congress that owns him, he doesn't have those rights. Thus, the "Click It or Ticket" program is simply Congress' way of caring for its property, the American people.
Whether seatbelt usage is a good idea is beside the point, for daily exercise, nutritious meals, eight hours sleep, and cultural and intellectual enrichment might also be good ideas. The point is whether government has a right to coerce us into taking care of ourselves.
If eating what we wish is our business and not that of government, then why should we accept government's coercing us to wear seatbelts? America's tyrants might answer, "We just haven't gotten around to dictating diets yet."
Some might argue, but falsely so, that the problem with people exercising their liberty to drive without seatbelts, ride motorcycles without helmets or eat in unhealthy ways is that if they become injured or sick, society will be burdened with higher health-care costs. That's not a problem of liberty but one of socialism.
There's no liberty-based argument for forcing one person to care for the needs of another. Under socialism, one is obliged to care for another. A parent-child relationship emerges between the citizen and the government. That was not the vision of our Founders.