The effect of the size of one and two traffic signs on two measures of perceptual performance

Abstract

A large object can delay the perception of a small object, which hints that the use of larger objects in general and larger traffic signs in particular may be counterproductive. The present study employed either one traffic sign or two contiguous traffic signs on a post in a photograph of a road scene. Identification of a small target sign was not slower when a second sign was contiguous than when there was only the one small target sign, regardless of whether the contiguous sign was large or small. Furthermore, when a counting task was used with the same stimuli, a large sign accelerated the response to two-sign stimuli, again regardless of the contiguous sign's size. In addition, the response lo two-sign stimuli was not slower than the response to one-sign stimuli. The large-small comparisons of both experiments reduce the concern that employing a large traffic sign will delay the perception of a second contiguous sign. Moreover, the one-two comparisons of both experiments imply that employing two contiguous signs will not delay the perception of a sign, despite widespread evidence that a nearby object will delay the perception of a target object.

Keywords:

• Automobile driving
• Size perception
• Form perception