The effect of Center High Mounted Stop Lamp (CHMSL) on rear-end accidents in Israel

Additional analyses evaluated the model year effect in greater detail, in order to determine whether there exists a change point between 1993 and 1994 as would be expected from a CHMSL effect, or whether the effect is spurious. Detailed analyses were performed on the ratio of struck to striking involvements as well as the rates of involvement of both types. These analyses showed that (1) the chosen reference measurement is an appropriate one, but (2) the 0.93 odds ratio is quite possibly due to other reasons unrelated to the CHMSL, thus further limiting the confidence in CHMSL effectiveness.