Psychological Load of Drivers in Entrance Zone of Road Tunnel Based on TOPSIS Improved Factor Analysis Method

To quantify and analyze the psychological reactions of drivers at the entrance zone of a road tunnel, drivers' physiological data (pupil area, saccade range, saccade speed, heart rate, and breathing rate) were collected using the eye-tracking system in a real driving environment. A psychological load model was developed to quantify the multiple psychological indicators and analyze the change of psychological load at different times and locations based on the TOPSIS (technique for order preference by similarity to an ideal solution) improved factor analysis method. Sensitivity analysis was used to explore the effect of psychological indicators on psychological load. Results of tests conducted at different times of day (12:00, 15:00, and 18:00) show that psychological loads increase slowly to 0.52, 0.38, and 0.23, respectively, when outside the tunnel entrance (from -100 m to -50 m), increase dramatically to a maximum value (1, 0.84, and 0.71) when approaching the tunnel entrance (from -50 m to 0 m), and decrease dramatically to 0.61, 0.58, and 0.41 when first entering the tunnel (from 0 m to 50 m), and then decrease slightly to 0.20, 0.13, and 0.12 when driving inside the tunnel (from 50 m to 200 m). The result also shows that the proportions of saccade speed, pupil area, and saccade range are larger than heart rate and breathing rate. Moreover, the psychological loads of drivers are considerably lower at 18:00 than at 15:00 and 12:00, and the psychological loads near the entrance are considerably larger than inside or outside the entrance.