Since 1977, U.S. states have passed laws mandating that children be restrained in child safety seats. Initially these laws typically applied to children ages one to three, but since the mid-1990s they have seen a huge ratcheting upwards. The median age for seat belts in U.S. states is now eight, despite multiple studies showing that child car seats are generally no more effective than seat belts in preventing death or serious injury for children above age two.