Travellers with mental disabilities are deterred from using public transportation due to difficulties in selecting and understanding the travel information provided. The aim of this research is to determine whether the standard use of pictograms could make their travel easier and under which conditions. Sign understanding was individually assessed in 81 subjects with varying reading and mental abilities. The ability of each subject to understand signs under the following conditions was assessed: 1) signs with pictograms, text or mixed information, presented in isolation from their usual environment (47 commonly used signs); 2) information data given on slides showing several transport environment conditions; 3) sign interpretation during a real-world unfamiliar multimodal trip. Standardized tests and experiments, especially developed for this study, were used to identify the cognitive factors which affect sign understanding. More than a half of the signs were identified, without any significant differences between signs with pictograms only and signs with written messages. The ability to read had a direct effect on the identification of written messages, but also of pictographic only messages. Subjects able to read fully interpreted over 80% of the information provided on slides, other subjects showed lower and rather contrasting performances. The real-world environment seemed to be helping as 83% of the travellers easily interpreted the major part of on-site signs.
Abstract