  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 conduct more studies to evaluate how bicyclist and pedestrian
behavior and physiological states change in different roadway designs and
contextual settings. Previous research highlights the advantages of Immersive
Virtual Environment (IVE) in conducting bicyclist and pedestrian studies. These
environments do not put participants at risk of getting injured, 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 ORCLSim,
to support human sensing techniques within IVE to evaluate bicyclist and
pedestrian physiological and behavioral changes in different contextual
settings. To showcase this framework, we present two case studies where we
collect and analyze pilot data from five participants' physiological and
behavioral responses in an IVE setting, representing real-world roadway
segments and traffic conditions. Results from these case studies indicate that
physiological data is sensitive to road environment changes and real-time
events, especially changes in heart rate and gaze behavior. Additionally, our
preliminary data indicates participants may respond differently to various
roadway settings (e.g., intersections with or without traffic signal). By
analyzing these changes, we can identify how participants' stress levels and
cognitive load is impacted by the simulated surrounding environment. The
ORCLSim system architecture can be further utilized for future studies in
users' behavioral and physiological responses in different virtual reality
settings.
