EFFECTS OF DRIVER-SIDE MIRROR TYPE ON LANE-CHANGE ACCIDENTS

This quasi-experiment was designed to investigate the effects of the t ype of driver-side mirror on lane-change accidents. The analysis was b ased on 407 accidents reported from 1987 to 1992 to Finnish insurance companies, for vehicles with passenger-side convex miners and one of t hree types of driver-side mirrors (flat, convex or multiradius). The r esults showed that there was no difference between the multiradius and convex mirrors in the frequencies of lane-change accidents to the lef t. Compared to the flat mirror, the mean effect of the multiradius and convex mirror was a 22% decrease. However, the statistical strength o f the data was low; 95% confidence interval ranged from a 51% decrease to a 25% increase. This result was not related to driver characterist ics or driving conditions. In conclusion, the multiradius and convex d river-side mirrors, in comparison to the flat mirror, are more likely to reduce than increase lane-change accidents. A theoretical implicati on of this study is that minimizing the blind spot is likely to be mor e important than providing an undistorted image of objects. From a pra ctical point of view, the present findings support the use of multirad ius and convex driver-side mirrors.