How to Present Paired Information on the HUD Interface: The Effects of Horizontal and Vertical Angles on Object Discrimination

Many studies have explored the influence of the position of a single piece of information in a head-up display (HUD) system on driving performance. However, few studies have evaluated the range of multiple visual angles. This study aimed to examine the positions and visual aspects of driving information presentation that enhance drivers’ driving performance. Considering the horizontal and vertical directions, we designed two experiments to identify an appropriate area to present driving information. Experiment A was designed as a 4 (horizontal angles: 10°, 20°, 30°, 40°) × 3 (vertical positions: −5°, 10°, 20°) within-subject experiment to evaluate the effects of the horizontal angle and vertical position of information on the reaction time and difficulty rating. The results showed that when the vertical position was −5° or 10° and the horizontal angle was 10°, the driver’s reaction time was faster and the driver felt easier. Experiment B was designed as a 3 (vertical angles: 5°, 15°, 25°) × 3 (horizontal positions: −15°, 10°, 25°) within-subject experiment to explore the effect of the vertical angle and horizontal position of the information on the reaction time and difficulty rating. The results showed that when the horizontal position was 10° and the vertical angle was 5°, the driver’s reaction time was faster and felt that the task was easier. The two experimental results showed that participants responded faster and rated the task as easier when information was placed near the center visual field. The results may be useful for designers to present multiple pieces of driving information on HUDs and provide theoretical guidance for HUD interface design.