Modulating driver visual behavior in highway tunnel groups through rhythm-based visual cues.

Objective: Drivers navigating highway tunnel groups face complex and repetitive lighting environments, which increase cognitive load and compromise safety. This study aimed to evaluate the effectiveness of rhythm-based visual cues in improving perceptual orientation and regulating driver visual behavior in tunnel group scenarios.

Methods: To determine the most suitable rhythm pattern for visual guidance, a rhythm adaptability selection process was first conducted using a fuzzy evaluation method. A simulated driving experiment was then performed in UC-win/Road, exposing participants to varying lighting conditions with and without rhythm-based visual cues. Driver eye-movement metrics, including fixation duration, saccade amplitude, and saccade velocity, were used as behavioral indicators to assess visual load and attention regulation.

Results: Extended tunnel driving was associated with increased fixation durations, a dominance of small-angle saccades (0°-10°), and slower saccade velocities-patterns indicative of visual fatigue and decreased attentional control. The introduction of rhythm-based visual cues significantly improved visual behavior by reducing fixation durations, lowering the frequency of small-angle saccades, and enhancing saccade dynamics. These improvements were more prominent under low-light conditions, indicating better visual adaptability and engagement.

Conclusions: Rhythm-based visual cues provide an effective and energy-efficient alternative to increased tunnel illumination by directly targeting visual behavior. The findings support the application of perceptually informed environmental design strategies that utilize rhythm sensitivity to improve driver safety in highway tunnel groups.