Study on traffic sign classification for assessing sign comprehension

Previous studies analyzed the relationship between drivers´ personal characteristics and their comprehension of traffic signs directly, but neglected to test and control the influence of small class of traffic signs themselves. This error might cause the distortion of research results. So a comprehensive survey of drivers´ comprehension of all warning signs was conducted in this paper. Average level of every warning sign comprehension was assessed. Warning signs were divided into four clusters using Hierarchical Cluster Analysis. The final classification scheme was determined based on significant difference test between clusters and homogeneity test within every cluster. Study results indicate that small class of traffic signs has certain influence on the level of traffic signs comprehension and it may inhibit the influence of drivers´ personal characteristics. The traffic signs classification scheme can solve this problem effectively. This study will provide foundation for the study of comprehension and design of traffic signs.