In the fall of 1971, safety belt usage (lap belt only or lap/shoulder combination) was observed for more than 9000 front seat occupants of certain late model automobiles in three medium-sized communities in California. Vehicles were observed in low speed and high speed driving situations and observations recorded accordingly. Data were obtained for Chrysler. Ford and General Motors passenger cars for model years 1968–1971. Belt configuration is defined across three design variables—(a) push-button vs lift-latch buckle; (b) manual vs automatic belt adjustment; and (c) three-point vs four-point belt. It does not appear that belt usage is a function of vehicle age or manufacturer. Moreover, at the 5 per cent significance level, only one of the 12 relevant tests supports the hypothesis that usage is a function of belt configuration. One additional test supports this hypothesis at the 10 per cent significance level.
Abstract