Can retroreflective rings enhance drivers’ safety perception of spatial right-of-way in freeway tunnels? A simulation exploration

In order to investigate whether retroreflective rings can enhance drivers’ perception of spatial right-of-way in freeway tunnels, this paper explores a simulation test. The characteristics of spatial right-of-way in tunnels are elucidated, and a comparative test is conducted using commonly used delineators and raised pavement markers against retroreflective rings to enhance the perception of spatial right-of-way. The test employs the perception of lateral deviation and longitudinal distance as indicators to reflect the lateral and longitudinal right-of-way. Video scenarios, incorporating different facilities and spacing, are created using 3Ds Max software following the design standards of freeway tunnels. The indicators of Stimulation of Subjectively Equal Distance (SSED), lateral deviation, and perception reaction time (PRT) are chosen to assess the effects of different facilities on drivers under varying spacing conditions. Fifty-two participants, divided into two groups of novice drivers and experienced drivers, underwent perception testing in a simulated driving environment. The results indicate that drivers exhibit the highest overestimation of longitudinal distance and the longest PRT of lateral deviation in the absence of facilities. Installing retroreflective rings with a spacing of 50–200 m significantly mitigates the overestimation of longitudinal distance, while reducing the PRT of lateral deviation. On the other hand, setting up delineators and raised pavement markers with a spacing of 6–12 m significantly reduces the PRT of lateral deviation, while there is no significant enhancement to the perception of longitudinal distance. A spacing of 200 m for retroreflective rings and 10 m for delineators and raised pavement markers in the straight section is recommended as a safer and more economical setting scheme. The combination of these facilities can enhance drivers’ safety perception of spatial right-of-way in freeway tunnels, facilitating rapid perception, correct judgment, and timely decision-making for the safe passage of vehicles.