This paper has focused on the vital issue of motivation with respect to traffic signs. As discriminative stimuli, signs can provide the driver with advanced information of required behavior in order to sustain a safe outcome. However, as potential controlling elements of driver behavior, signs are, to varying extents, in competition with naturally occurring discriminative stimuli; they frequently signal uncertain contingencies between behavior and its consequences. To be more effective, signs need to represent in a reliable way prevailing contingencies. However, when compliance with posted speed restriction is required, this may mean introducing additional contingencies, such as enforced penalties, to those occurring in the natural environment. To be effective, signs must, of course, also be detected and recognized. Although research has generated enough knowledge in this are to enable society to be prescriptive about detailed features of sign design and location, the exploitation of new assistive technologies has the potential to significantly enhance the impact of traffic signs on driver behavior.
Abstract