Study on the Drivers' Recognition Law under Different Lighting Environment along the Tunnel Exit Section at Nighttime

The poor design of the lighting environment along the tunnel exit section at nighttime could result in that drivers cannot recognize the road condition and obstacles, which is not safe and comfort for drivers. Lots of attention have been focused on the lighting environment of the entrance section and the middle section. This study was trying to examine the drivers’ recognition law under different lighting environment along the tunnel exit section at nighttime. Five levels of color temperatures (3000K, 4000 K, 5000 K, 5700K and 6500K) and three kinds of color-rendering indexes (70, 80, 90) were selected, and the brightness of the lights was adjusted in order to obtain different lighting environments. The non-contact speedometer was used to record driving speeds and distance, and the spectral irradiance meter was adopted to measure the parameters of lighting resources, and the dynamic eye tracker was used to record the drivers’ visual information. Twelve qualified drivers drove the typical car according to the task procedure. 168 effective tested data were obtained. The results indicated that the value of the luminance difference decreases with the increase of color temperature under the three types of color-rendering indexes. The value of the luminance difference increases with the increase of color-rendering index under the five levels of color temperatures. The smallest value of the luminance difference is 2.5 when the combination set is 6500K/70. When the color temperature is 3000K, the values of the luminance difference was about 4 under the three types of color-rendering indexes. The result of this study can provide guidance for the design and optimize the light setting of the tunnel exit section at nighttime.