This laboratory study evaluated the effect of three types of driver-side, exterior mirrors on drivers' response times for detection of cars at near distances in the left adjacent lane. The mirrors were a flat mirror, a convex mirror, and a multiradius mirror. All mirrors were of the same size and reflectivity. The drivers' visual field in the mirrors extended diagonally to the left about 20° for the flat mirror, 28° for the convex mirror, and 40° for the multiradius mirror. Consequently, there was a large blind spot using the flat mirror, a smaller blind spot using the convex mirror, but no blind spot using the multiradius mirror. The primary task was to respond as quickly as possible to the presence or absence of a car in a photograph projected on a large screen behind the subject (A secondary task involved compensatory tracking). The subjects responded by pushing one of two response buttons, depending on the presence or absence of the car. Time was measured from the onset of the photograph's appearance to the subject's response. The main result is that the response times were shortest when using the multiradius mirror and the longest when using the flat mirror. This was the case for younger and older subjects, as well as for American and Swedish subjects. (A)
Abstract