Dynamic Visual Warning Cues and Monochrome Gradient Types: Key Factors Shaping AR-HUD Warning Interface Design for Drivers

With the widespread application of Augmented Reality Head-Up Displays (AR-HUDs) in automotive systems, optimizing their visual warning interface design is critical for enhancing driving safety and user experience. This study investigated the effects of dynamic visual cues (static, single flash, continuous flash) and monochromatic gradient effects on drivers’ time perception and subjective evaluations (e.g., confidence, attractiveness, willingness). In a <tex-math notation="LaTeX">2× 3 </tex-math> between-subjects experiment with 162 participants, we simulated four driving scenarios and measured responses using questionnaires and semi-structured interviews. Two-way ANOVA results revealed indicated that: 1) Dynamic cues (single/continuous flash) significantly improved time perception compared to static cues, with no difference between single and continuous flashes; 2) Monochromatic gradients enhanced willingness and perceived performance; 3) Monochrome gradients improved time perception and subjective experience for static/single flash cues, while continuous flash cues performed better without monochrome gradients; 4) Significant interactions existed between cue types and monochrome gradients for interest and attractiveness. These findings highlight context-dependent optimization strategies for AR-HUD design, balancing salience reduction and situational awareness enhancement to improve driving safety and user experience.