This paper describes how a wide variety of methods are used to evaluate traffic signs. The effectiveness of traffic signs (or lack of it) can be enhanced only when perceptual and motivational factors are taken into account. In terms of practical consequences, several methods of improving traffic sign effectiveness were suggested. These were: repeating the sign (and paying greater attention to effective sequences of signs), implementing new signs, adding colored borders to signs, and reducing the "visual clutter" of many transport environments. Overall, the paper stressed that controlled testing of signs from the perspective of the human transport operator within a complex sociotechnical system is needed; new sign designs (or redesigns) must take into account humans' strengths and weaknesses as well as the varying demands of driving tasks. This will remain especially important in the future with the changing nature of the road environment, in which optimal Intelligent Transport Systems and Variable Message Signs will be realized only if they are designed and tested from a wide-ranging, driver-centered perspective.
Abstract