城市水下特长隧道出入口视觉及舒适性研究

为探求驾驶人在城市水下特长隧道出入口的视觉负荷变化特性和视觉舒适性，在上午9：00~10：00的平峰时段，天气良好且交通流影响较小的条件下，选取10名驾驶人于东湖隧道（全长10.6 km，限速60 km·h^-1）以50~60 km·h^-1的自由流车速开展实车试验。利用眼动仪、照度计等试验设备，采集驾驶人进出城市水下特长隧道过程中的瞳孔面积、照度值等试验数据。基于实车试验数据，研究进出隧道过程中驾驶人的瞳孔变动特性，并比较多种评价指标的差异性，选取瞳孔面积最大瞬态速度值为评价指标，对东湖隧道出入口的视觉舒适度进行评价。基于瞳孔面积的变化特点构建了瞳孔面积最大瞬态速度值与瞳孔面积的函数模型，具体分析了出入隧道过程中不同位置的视觉负荷。结合出入口处连续时间序列下光环境的变化特点，分析了出入口的视觉舒适性。研究结果表明：进入隧道过程中驾驶人瞳孔面积的平均增长率较城市普通路段增大至246.561%并趋于稳定，对黑洞效应的适应时间为8.636 s；驶离隧道过程中较隧道内部路段平均增长率减小至62.631%并趋于稳定，对白洞效应的的适应时间为4.273 s；瞳孔面积最大瞬态速度值与瞳孔面积呈正相关性，出入口位置的视觉负荷排序为入口洞内最大、出口洞内次之、入口洞外与出口洞外最小，各区段的视觉舒适性与之相反；研究发现出入口处的格栅式遮光棚可缓解光环境的急剧变化，有助于驾驶人适应黑白洞效应、提升行车安全性。

Visual Characteristic and Comfort at the Entrance and Exit of the Extra-long Urban Underwater Tunnel

To explore a driver's visual load change characteristics and visual comfort at the entrance and exit of an extra-long urban underwater tunnel, 10 drivers were selected for a real vehicle test. The test was performed at a free-flow speed of 50-60 km·h^-1 in the East Lake Tunnel (length:10.6 km; speed limit:60 km·h^-1) during the off-peak hours of 9:00-10:00 a.m. with good weather and little impact of traffic flow. An eye tracker and illuminometer were used to collect the experimental data, such as pupil area and illuminance value when entering and exiting the tunnel. Based on real vehicle test data, the drivers' pupil variation characteristics when entering and exiting the tunnel were studied. The differences between various evaluation indicators were compared, and the maximum transient velocity value of the pupil area wasselected as the evaluation index to evaluate the visual comfort at entrance and exit of the East Lake Tunnel. Based on the variation of the pupil area, a function model of maximum instantaneous velocity and pupil area was constructed, and the visual load at different positions while entering and exiting the tunnel was analyzed. The driving safety was analyzed by combining the variation characteristics of illumination under the continuous time series at the entrance and exit. The results show that the average growth rate of a driver's pupil area increases to 246.561% and tends to be stable when entering the tunnel. The adaptation time to the black hole effect is 8.636 s. The average growth rate of the pupil area while exiting the tunnel decreases to 62.631% and tends to be stable. The adaptation time to the white hole effect is 4.273 s. The maximum transient velocity value of the pupil area is positively correlated with the pupil area. The largest visual load occurs inside the tunnel at the entrance, followed by the exit, and the smallest visual load is outside the tunnel at the entrance and exit. Furthermore, the visual comfort of each section is opposite. The grille shading shed at the entrance and exit can alleviate the drastic changes of light environment and help the drivers adapt to the black and white hole effects and improve the driving safety.