EVACUATION BEHAVIOR AND SAFETY EGRESS ANALYSIS IN TUNNEL FIRES: A VIRTUAL REALITY SIMULATION STUDY

19th WORLD CONFERENCE OF THE ASSOCIATED RESEARCH CENTRES FOR THE URBAN UNDERGROUND SPACE, Belgrade, Serbia, November 4-7, 2025. (Paper No: 4.7.110,  pp. 713-727)

 

АУТОР(И) / AUTHOR(S): Vasilis Kotsakis, Christos Froudakis, Anastasios Kallianiotis, Maria Menegaki, Dimitrios Labrakis

 

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DOI:  10.46793/ACUUS2025.4.7.110

САЖЕТАК / ABSTRACT:

The rapid development of underground transport tunnels is accompanied by the inevitable risk of road accidents, which can result in major fires. The required safety egress time (RSET) is a critical parameter in designing fire mitigation strategies for tunnels. In these environments, where visibility is severely reduced due to smoke, evacuation behavior—including pre-evacuation time, encompassing alarm response, reaction time, and vehicle abandonment—plays a significant role in overall safety. This study employed a virtual reality (VR) simulation in Unreal Engine of a full-scale road tunnel, paired with computational fluid dynamics (CFD) modeling, to examine occupant behavior during tunnel fires across different scenarios. These scenarios varied based on smoke presence, alarm activation speed, and proximity to the fire source. The key factors analyzed were: (a) evacuation decision-making, (b) pre-evacuation time, and (c) route-finding strategies. The results indicate that pre-evacuation time is influenced by the type of emergency warning signals, smoke spreading, alarms, and occupants’ behavior. Most participants relied on exit signs to navigate their way out. However, smoke-filled routes often led some individuals to bypass nearby exits in favor of more distant ones, revealing important implications for tunnel design and safety planning.

КЉУЧНЕ РЕЧИ / KEYWORDS:

tunnel vehicle accident, virtual reality experiment, evacuation behavior, evacuation time

ПРОЈЕКАТ / ACKNOWLEDGEMENT:

The authors would like to all staff members and student of Mining Engineering and Environmental Mining laboratory for supporting the experimental procedure. In addition, they would like to extend a special note of appreciation to Thunderhead Engineering group, for providing educational license to use and work on Pathfinder and Pyrosim platform as well as for the excellent and direct cooperation of its members.

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