Research on the visual cognition patterns of exit guide sign viewing on freeway interchanges

The development of freeway construction and the increasing coverage of the road network have led to increasing requirements for guide signs. This article investigated drivers’ visual cognition pattern regarding exit guide signs on freeway interchanges. A static visual cognition experiment with 32 participants was carried out. The route information volume (four levels) and destination information volume (seven levels) were selected as the variables. An eye-tracking system was utilized to record drivers’ eye movement indicators, such as eye movement time, saccade frequency, seek time, and fixation duration. The results indicated that the eye movement time, saccade frequency, and seek time are highly correlated with information volume and increase significantly with the increases in information volume; although the fixation duration has no correlation with information volume, the fixation duration value, saccade frequency, and seek time of destination information are significantly higher than those of route information, and the destination information fulfills a stronger guiding function during the driver’s trip. The corresponding threshold values of destination information are 5, 5, 4, and 3 under the four levels of route information, and the threshold value of route information is 3.