Study on drivers' visual characteristics under visual composite elements at highway tunnel entrance section

To investigate the impact of visual composite elements, including guiding and warning elements, on drivers' visual characteristics at the entrance section of a highway tunnel, on-road vehicle experiments were conducted at a highway tunnel in Hubei Province. Visual composite elements were installed at the southbound entrance section while no elements were arranged at the northbound entrance section. Fine-grained eye-tracking data, including gaze duration and scanning angle, were collected from 18 drivers at both the southbound and northbound tunnel entrance sections to analyze differences in their visual characteristics. The results indicate that drivers had longer gaze durations and more concentrated gaze distributions at the northbound entrance section, whereas gaze durations were shorter and gaze distributions were more dispersed at the southbound entrance section. Furthermore, drivers exhibited larger scanning angle during the driving process at the southbound entrance section, while demonstrating smaller scanning angle and faster scanning speeds at the northbound entrance section. Overall, the installation of visual composite elements significantly influenced drivers' eye movement indicators, allowing drivers to more effectively gather driving-related information, reduce driving stress, and enhance visual stability while driving.