  Humans make their evacuation decisions first at strategic/tactical levels,
deciding their exit and route choice and then at operational level, navigating
to a way-point, avoiding collisions. What influences an individuals at tactical
level is of importance, for modelers to design a high fidelity simulation or
for safety engineers to create efficient designs/codes. Does an unlit exit sign
dissuades individual(s) to avoid a particular exit/route and vice versa? What
effect does the crowd's choices have on individual's decision making? To answer
these questions, we studied the effect of exit signage (unlit/lit), different
proportions of crowd movement towards the exits, and the combined
(reinforcing/conflicting) effect of the sign and the crowd treatment on
reaction times and exit choices of participants in an immersive virtual
reality(VR) evacuation experiment. We found that there is tolerance for queuing
when different sources of information, exit signage and crowd movement
reinforced one another. The effect of unlit exit signage on dissuading
individuals from using a particular exit/route was significant. The virtual
crowd was ineffective at encouraging utilization of a particular exit/route but
had a slight repulsive effect. Additionally, we found some similarities between
previous studies based on screen-based evacuation experiments and our VR-based
experiment.
