Tempered versus HPR Laminated Windshields: A Comparative Study of United Kingdom and United States Collisions

Data are presented from two field studies on the collision injuries which result from contact with tempered glass and 0.030 in. (0.76 mm) high penetration resistant (HPR) laminated glass windshields. Two sets of similar automobile collisions are analyzed. The first set consists of European and Japanese cars imported into the United States (in Southern California). The second set is drawn from a study of British cars involved in collisions in England, all of which had tempered windshields.

The frequency and severity of injury from the windshield are given for each set of collisions. Comparisons are made on the basis of vehicle damage and equivalent impact speeds. Examples of the mechanisms of injury for the two types of glass are outlined.

The data presented indicate that tempered windshields give rise to a higher incidence of injury and more severe injuries than the 0.030 in. HPR laminated windshields under similar impact conditions. These differences are statistically significant. The importance of severe injuries from the edges of shattered tempered windshields is discussed, together with injuries which result from the passing of occupants through the plane of the windshield to strike the car hood or cowl.

Eye injuries from the two types of windshields are discussed, together with the effect on the injury mechanisms when the windshield becomes detached during the collision.