Is the street-crossing behavior with a head-mounted display different from that behavior in a CAVE? A study among young adults and children

Abstract

Abstract The use of virtual reality (VR) has become increasingly popular in the field of traffic psychology, where realistic traffic situations can be simulated and pedestrians‘ actual crossing behavior can be studied. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE); the other uses a head-mounted display (HMD). Despite their extensive use, it is yet to determine whether they are equally suitable for studying street crossing. The present study was aimed at comparing street-crossing behavior and subjective evaluations in an HMD-based (HTC vive pro) pedestrian simulator and a CAVE-like pedestrian simulator, among young adults and 12-year-old children. Thirty young adults and twenty-six children performed 36 street-crossing trials (combining different speeds, traffic conditions, and gap sizes) on each of the two simulators. The results indicated that, compared to the CAVE-condition participants, HMD-condition participants accepted more crossing trials (hence, shorter gaps), initiated their crossings sooner, crossed at a slower speed, had shorter safety margins, and caused more collisions. The main difference between the two devices was in crossing initiation, which occurred markedly earlier (1.72\xa0s) with the HMD than in the CAVE: the perception–action coupling was less finely tuned in the CAVE, probably because visual information in front of the pedestrian was missing due the absence of ground projection and 3D rendering. A significant effect of vehicle-approach speed was observed for both devices, with more unsafe behaviors at 60\xa0km/h than at 40\xa0km/h. Children displayed riskier crossing behavior than young adults did, with more accepted crossings, slower crossing speeds, shorter safety margins, and higher collision rates, especially in the HMD. Compared to the CAVE, the HMD received higher ratings for level of presence and a preference for VR, but also higher simulator-sickness scores. No adverse effects of exposure to virtual reality was found on stereoacuity or postural balance. The suitability of using CAVE and HMD simulators is discussed, especially for studying child pedestrians.