基于眼动特征的信号交叉口老年人等待过街精神负荷分析

为适应我国老龄化社会的到来，对比年轻人，分析了老年人在信号交叉口面对不同过街场景时精神负荷情况。针对不同的交通环境，选取重庆市南岸区内3个交叉口8个进口道的8张不同的图片作为实验场景的刺激物，并利用眼动仪采集了年轻人和老年人两类行人的注视、眨眼、瞳孔直径等数据。本文通过因子分析，采用注视总时长百分比、眨眼频率以及平均瞳孔直径作为评价两类行人过街精神负荷的典型指标，对行人等待过街时精神负荷进行量化。结果表明，两类行人在面对部分场景时，注视总时长百分比、眨眼频率和平均瞳孔直径均存在显著差异；老年人精神负荷最大为场景2(1.38)；两类行人的精神负荷相对差值最大的为场景4，老年人高于年轻人55.02%；面对不同过街场景时，年轻人的精神负荷的变化更为敏感；部分精神较为紧张的老年人更容易受到信号灯和路桩的影响；相比于场景2中的过街等待部分台阶和缓坡，老年人对场景4中的黄色台阶和深色缓坡投入更多注意力(16.59%)；老年人在场景6、7中对远处车辆的注视时间百分比分别为17.84%和17.62%，说明老年人对远处车辆的注视时间百分比并不受近处行人的影响；老年人对场景2中的灰色路桩注视时间百分比为20.44%，对场景8中的蓝白色路桩注视时间百分比为27.01%，说明醒目的路桩可以显著提升老年人对远处安全设施的注意力。研究结果可以为提升老年人过街的安全性设置提供一定的参考。

Mental Load Analysis of Elderly People Waiting to Cross the Street at Signalized Intersection Based on Eye-movement Characteristics

In order to adapt to the arrival of the aging society, the mental load of elderly people facing different crossing scenarios at signalized intersections was analyzed in comparison with young people. For different traffic environments, 8 different pictures of 8 inlet lanes at 3 intersections within the Nanan District of Chongqing were selected as stimuli for the experimental scenes. Eye tracker was used to collect the data of gaze, blink and pupil diameter of two types of pedestrians. In this paper, the mental load of pedestrians waiting to cross the street was quantified by factor analysis, using the percentage of total gaze duration, blink frequency and mean pupil diameter as typical indicators to evaluate the mental load of 2 types of pedestrians crossing the street. The results shows that the percentage of total gaze duration, blink frequency and average pupil diameter are significantly different between the 2 types of pedestrians when facing some scenarios. The greatest mental load of the elderly is scene 2 (1.38). The greatest relative difference between the mental loads of the 2 types of pedestrians is scene 4, which is 55.02% higher for the elderly than for the young. The change in mental load of the young is more sensitive when facing different crossing scenes. Some of the elderly who are more mentally stressed are more likely to be influenced by signals and road stakes. Compared to waiting for some steps and gentle slopes in Scene 2, elderly people devote more attention to yellow steps and dark gentle slopes in Scene 4 (16.59%). The percentage of time elderly people spend gazing at distant vehicles in scenes 6 and 7 is 17.84% and 17.62%, respectively, indicating that the percentage of time elderly people spend gazing at distant vehicles is not influenced by near pedestrians. The percentage of time elderly people spent gazing at gray road stakes in scene 2 is 20.44% and at blue and white road stakes in scene 8 is 27.01%, indicating that eye-catching road stakes can significantly enhance the attention of elderly people to distant safety facilities. The results of the study can provide some reference for improving the safety settings of elderly people crossing the street.