Abstract:   A driver’s ability of perceiving and comprehending traffic signs is affected by his/her mental workload and the information volume of the traffic signs.In this paper,a novel method is proposed to determine the information volume.By a simulation experiment for the process of driving to the destinations with the guide of traffic signs in Beijing,it is shown that the proposed method fits the subjective rating of the information volume well.Further analysis indicates that 1) the effect of the information volume is insignificant,2) the effect of mental workload on sign identification rate,decision time,accuracy,and confidence ratings is significant,and 3) the effect on perceived task load and sign detection time is insignificant.

Key words: traffic signs, perception and comprehension, information volume, mental workload