How do different seasonal environmental colors of highway tunnel entrances and dominant colors of portal walls affect the driver’s vehicle control ability?

The entrance section of the highway tunnel is a high-risk area for traffic accidents, and its traffic accident rate has significant seasonal differences. However, the dominant causes of this difference are still lacking in targeted research. On the other hand, due to the lack of a mature design system and normative guidance, the landscape design of tunnel entrances is more and more random, landscape elements tend to be complex, and color design tends to be diversified. The influence of tunnel entrance landscape design on driving behavior and its applicability in different seasonal environments needs to be studied. Given this, this study focused on two main variables − the typical seasonal environmental colors and different portal colors, and designed 12 schemes composed of three seasonal environments (green spring, golden yellow and red autumn, and white winter) and four portal colors (gray, blue, red, and tawny). Thirty subjects were invited to conduct a driving simulation experiment to study the influence of different seasonal environmental color characteristics and tunnel portal color on the amplitude and stability of driving behavior. The results show that the drivers’ behavior amplitude is large in spring and winter, and the traffic safety risk is relatively high. The typical color characteristics of the environment in different seasons are one of the reasons for the seasonal difference in the traffic accident rate. The driver’s operational stability is relatively poor in the autumn environment, which is related to the high scene complexity of the season. Compared with the grey portal scheme, the color design of the portal will increase the driver’s driving speed and the driving safety risk. However, its influence on the stability of driving behavior is bidirectional, and the color design coordinated with the environment can improve the stability of driving. When the portal is ready for landscape decoration, it is recommended to use a color scheme that is in harmony with the environment.