Graphical symbols are commonly used in signage systems for public areas and city maps. The ability of the symbols to convey a clear and unambiguous message is crucial for their effectiveness, especially when they are intended for the tourists with specific needs. In this study, a comprehensibility judgement test was used to determine the interpretability of three new proposals for the city signage symbols. Ninety-six adults in the age range between 19 and 65 years with a diverse educational background participated in the experiment as evaluators. Two age groups and four education levels were used as independent variables. Contrary to expectations, the results showed no significant effect of age on the participants’ judgement scores. In contrast, the judgement scores were influenced by the education level to a certain degree. Two major findings can be derived from the results. First, the judgement test confirmed an acceptable level of comprehension score for a new graphical symbol for the tourists with specific needs, which was reported in previous research, demonstrating its potential for practical application in future development of different signage solutions. Second, the results indicated that participants’ education background should be taken into consideration when selecting the appropriate sample size in symbol comprehension testing.