ORCLSim: A System Architecture for Studying Bicyclist and Pedestrian Physiological Behavior through Immersive Virtual Environments

Abstract

Injuries and fatalities for vulnerable road users, especially bicyclists and pedestrians, are on the rise. To better inform design for vulnerable road users, we need to evaluate how bicyclist and pedestrian behavior and physiological states change in different roadway design and contextual settings. Previous research highlights the advantages of using immersive virtual environments (IVEs) in conducting bicyclist and pedestrian studies. These environments do not put participants at risk of injury, are low cost compared to on-road or naturalistic studies, and allow researchers to fully control variables of interest. In this paper, we propose a framework, Omni-Reality and Cognition Lab Simulator (ORCLSim), to support human sensing techniques within IVEs to evaluate bicyclist and pedestrian physiological and behavioral changes in different contextual settings. To showcase this framework, we present two case studies, where pilot data from five participants’ physiological and behavioral responses in an IVE setting are collected and analyzed, representing real-world roadway segments and traffic conditions. Results from these case studies indicate that physiological data are sensitive to road environment changes and real-time events in the IVE, especially changes in heart rate and gaze behavior. In addition, our preliminary data indicate participants may respond differently to various roadway settings (e.g., signalized vs. unsignalized intersections). By analyzing these changes, future studies can identify how participants’ stress level and cognitive load are impacted by the surrounding environment. The ORCLSim system architecture is a prototype that can be customized for future studies in understanding users’ behavioral and physiological responses in virtual reality settings.

Rethinking infrastructure design: evaluating pedestrians and VRUs’ psychophysiological and behavioral responses to different roadway designs

“…The various ways of interactions will be evaluated by users' stated preferences and objective responses as well. Moreover, based on our framework 27 , it is possible to include multiple agents in the IVE, so other road users such as bicyclists and drivers can be studied together with pedestrians within the IVE. We are developing a multi-agent simulator for different road users (more pedestrians, cyclists, work zone workers, and drivers) based on the current system framework, aiming to study the pedestrian platoons simultaneously in the same VR environment.…”

Rethinking infrastructure design: Evaluating pedestrians and VRUs' psychophysiological and behavioral responses to different roadway designs

“…The various ways of interactions will be evaluated by users' stated preferences and objective responses as well. Moreover, based on our framework 38 , it is possible to include multiple agents in the IVE, so other road users such as bicyclists and drivers can be studied together with pedestrians within the IVE.…”

“…HTC Vive Pro Eye headsets with the controllers are utilized for any interactions in the IVE. More detailed information of the IVE setup is available in our previous studies 38,40,41 . Vehicle traffic within the IVEs is generated from empirical gap acceptance data observed at the real-world Figure 5.…”

“…The data collection method of this study follows the framework of our previous study 38 , different types of behavioral and physiological data are collected: stated preferences from pre and post experiment survey, crossing behavior data from Unity, eye tracking data from Tobii Pro Eye headset, heart rate data from smartwatches.…”

“…The other variables have the same definitions as in the SGE equation (1). More details of calculating SGE and GTE can be found in 38,43 .…”