： 为进一步分析低等级公路光学长隧道内不同车型、不同隧道区域驾驶员的视觉负荷特性，招募了22名驾驶员（12名小汽车驾驶员、10名货车驾驶员），选取云南省境内的昔宜隧道开展低等级公路光学长隧道驾驶员实车试验。利用眼动仪采集驾驶员瞳孔面积的相关数据，应用双因素方差分析对数据进行小汽车与货车、入口段与出口段的差异性显著检验，并分析驾驶员瞳孔面积变化速率的整体变化规律；同时，借助变异系数来反映驾驶员的适应能力。结果表明： 1）隧道入口段和出口段之间以及小汽车与货车驾驶员之间的瞳孔面积变化速率均值存在显著性差异，车型（小汽车和货车）与隧道区域（入口段和出口段）2类因素之间对瞳孔面积变化速率无交互影响； 2）货车驾驶员在进出隧道时视觉负荷更严重，货车驾驶员在隧道内的瞳孔面积增大与减小变化率峰值均大于小汽车驾驶员； 3）货车车型和出口区域的驾驶员对视觉环境更为敏感，不同车型、不同隧道区域驾驶员的瞳孔面积变化速率变异系数有显著差异。

In order to analyze the visual load characteristics of different models and regions in lowgrade highway optical long tunnels, 22 drivers (12 car drivers and 10 truck drivers) are selected for real vehicle experiments of lowgrade highway optical long tunnel by taking Xiyi Tunnel in Yunnan province for example. The pupil area data of the drivers are collected by eye tracker; the significant differences of car and truck drivers at the entrance and exit section are tested by using twoway analysis of variance; the overall variation of drivers′pupil area varying rate is analyzed; and the adaptability of drivers is reflected by coefficient of variation. The results show that: (1) There is a significant difference in the average rate of variation in pupil area between the entrance and exit sections of the tunnel and the drivers of the car and the truck; and there is no interaction between the two factors in the tunnel area in terms of the rate of variation in pupil area. (2) The visual load of the truck driver in the tunnel is more serious, and increase and decrease of the peak rate of the pupil area in tunnel is greater than that of the car driver. (3) The truck model and the exit area are more sensitive to the visual environment for the driver in the highway tunnel; and the drivers of different vehicle types and different tunnel areas have significant differences in terms of the variation coefficient of the pupil area varying rate.