The Effects of Chevron Alignment Signs on Characteristics of Drivers′ Eye Movement: An Experimental Study on Prairie Highways

Chevron alignment signs on prairie highways play a significant role in directing changes of road alignment, inducing sight of drivers, relieving visual monotony, and improving driving safety.Different curve sections on a prairie highway are selected, and indicators of eye movement are collected from seven drivers using eye tracking system.The data of five drivers are recognized as valid.A One-way ANOVA analysis is applied to filter sensitive indices considering the influence of different factors.The results indicate that pupil diameter is sensitive to the existence of chevron alignment signs and gender of drivers;while saccade amplitude is sensitive to the positions of chevron alignment signs.When no chevron alignment sign exists, the average pupil diameter is 0.09 mm, higher than that with chevron alignment signs.The pupil diameter changes in a wide range with variance of the average rate of change about 0.5%.When chevron alignment signs are positioned on the left side, the saccade amplitude is 2.59° higher than on the right side.And variance of the average rate of change is about 1.3%.Female drivers are found to be more concentrated, with a larger (0.25 mm) pupil diameter, and variance of the average rate of change is 0.7%.