Seat belt that required a particular technical approach would rapidly become dated as motor manufacturers would tool up for a particular standard which could not easily be changed. For example, in 1969 there were competing designs for lap and three-point seat belts, rapidly tilting seats, and airbags being developed. But as countries started to mandate seat belt restraints the global auto industry invested in the tooling and standardized exclusively on seat belts, and ignored other restraint designs such as air bags for several decades As of 2016, seat belt laws can be divided into two categories: primary and secondary. A primary seat
Which? centres during the 1970s. More than 120 such centres were operating in 1977-8, many of them funded by local councils. The centres closed as funding was withdrawn by the government in 1980. "Which?" continued campaigning on consumer safety issues, with its car safety test results strengthening calls to legislate car manufacturers to fit seat belts in all new cars, helping to make it compulsory to Clunk Click Every Trip in 1983. In 1992, "Which?" launched another satellite publication, this one aimed at youngsters aged 11–15, called Check It Out!, but it failed to take off and closed in June 1994.