Cognitive Design Features on Traffic Signs

success of effective communication of traffic sign messages to road users may not only relate to the user characteristics but also the signs themselves. The purpose of this experiment was to examine the cognitive design features of 120 Mainland China traffic signs. The features included familiarity, concreteness, simplicity, meaningfulness, and semantic closeness. Forty-one Hong Kong Chinese engineering undergraduates, who have never taken any driving tests, nor possessed any driving licenses in any places, voluntarily participated in this experiment. For each sign, subjects were asked to give subjective ratings between 0 to 100 points for familiarity (0 = very unfamiliar, 100 = very familiar), concreteness (0 = definitely abstract, 100 = definitely concrete), simplicity (0 = very complex, 100 = very simple), meaningfulness (0 = completely meaningless, 100 = completely meaningful), and semantic closeness (0 = very weakly related, 100 = very strongly related). With the exception of familiarity, the mean ratings on the other four sign features for all signs were above the midpoint (50) of the 0-100 rating scale. The below the mid-point rating (43.87) on familiarity showed that the subjects were not quite familiar with the chosen Mainland China traffic signs. the selected traffic signs were perceived to be moderately concrete, simple and meaningful, and related to their intended meanings. Significant and positive relationships were found amongst the cognitive sign features of familiarity, concreteness, meaningfulness, and semantic closeness. Other than with familiarity, simplicity did not correlate with the other four features. The box plot may be used as a tool for identifying unusual signs for in-depth analysis and for guiding designers to develop new traffic signs at the design stage. The results suggested that cognitive design features are useful for designing more user-friendly traffic signs, which should transmit clear messages about road conditions ahead at the right time to road users. Further research efforts will be given in investigating the effect of sign features on sign comprehension.