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
Seat belt legislation be fitted with seat belts. In one such attempt in 1979 similar claims for potential lives and injuries saved were advanced. William Rodgers, then Secretary of State for Transport in the Callaghan Labour Government (1976–1979), stated: "On the best available evidence of accidents in this country - evidence which has not been seriously contested - compulsion could save up to 1000 lives and 10,000 injuries a year." In the United States, seat belt legislation varies by state. The state of Wisconsin introduced legislation in 1961 requiring seat belts to be fitted to the front outboard seat positions of cars. Seat