Luminous Performance and Quantity Optimization of Exit Signs in Buildings: Balancing Visibility and Emergency Evacuation Efficiency

Abstract

Emergency evacuation signage, particularly exit signs installed along building corridors and evacuation routes, is critical for life safety during emergencies. Traditional signage design generally prioritizes maximizing visibility and spatial coverage. However, excessive sign installation may introduce visual clutter and interference among overlapping guidance cues, thereby limiting further improvements in evacuation performance. Therefore, a two-stage method is proposed to explore the optimal balance between luminous performance, installed quantity, and spatial distribution of exit signs for efficient evacuation guidance. First, a controlled experiment involving 30 participants was conducted to establish a U-shaped psychophysical relationship between achromatic contrast and the maximum recognition distance (MRD). The relationship is largely independent of both ambient illumination and observer gender. Second, the MRD data were integrated into Pathfinder to systematically assess how occupant density and sign quantity jointly influence evacuation efficiency. The results demonstrate that the optimal signage configuration shows significant density dependence. In the tested corridor scenario, three signs yield the shortest evacuation time at high occupant density, whereas fewer signs achieve comparable or better evacuation performance at medium and low densities. Moreover, a saturation effect is identified in the benefits of MRD improvement. Once the threshold is exceeded, further increases in MRD yield little or no additional improvement in evacuation efficiency. These findings are discussed in terms of hypothesized interference from overlapping guidance cues and congestion from overlapping signs. The study suggests that future signage design guidelines may benefit from incorporating density responsive and performance-based evaluation. Further experimental and field validations are needed to support broader standardization.

Keywords

Agent-based simulation / Building corridor / Emergency evacuation efficiency / Exit sign / Maximum recognition distance

References

[1] Bai, X., L. Hu, and Q. Ma. 2024. Can’t ignore surrounding shapes: Neural processing mechanisms of safety sign designs. Safety Science 177: Article 106594.

[2] Beattie S, Xi JYS, Chan WKV. On effective campus attack response: Insights from agent-based simulation for improving emergency information sharing system design and response strategy. International Journal of Disaster Risk Science, 2022, 13(3): 435-447.

[3] Bernardini, G., R. Lovreglio, E. Quagliarini, and M. D’Orazio. 2023. Can active and passive wayfinding systems support fire evacuation in buildings? Insights from a virtual reality-based experiment. Journal of Building Engineering 74: Article 106778.

[4] Boyce RR, Mulder MMC. Effective directional indicators for exit signs. Journal of the Illuminating Engineering Society, 1995, 24: 64-72.

[5] Ding, Z., S. Xu, X. Xie, K. Zheng, D. Wang, J. Fan, H. Li, and L. Liao. 2024. A building information modeling-based fire emergency evacuation simulation system for large infrastructures. Reliability Engineering & System Safety 244: Article 109917.

[6] Filippidis, L., H. Xie, E.R. Galea, and P.J. Lawrence. 2021. Exploring the potential effectiveness of dynamic and static emergency exit signage in complex spaces through simulation. Fire Safety Journal 125: Article 103404.

[7] Frome FS, Buck SL, Boynton RM. Visibility of borders: Separate and combined effects of color differences, luminance contrast, and luminance level. Journal of the Optical Society of America, 1981, 71: 145-150.

[8] Fu, M., R. Liu, and Q. Liu. 2023. How individuals sense environments during indoor emergency wayfinding: An eye-tracking investigation. Journal of Building Engineering 79: Article 107854.

[9] Gao, D., E.W.M. Lee, and Y.Y. Lee. 2023. The influence of context effects on exit choice behavior during building evacuation combining virtual reality and discrete choice modeling. Advanced Engineering Informatics 57: Article 102072.

[10] Hong WH, Jeon GY. A study on safe egress countermeasure in underground space through the analyzing survivors’ exit patterns of Daegu city subway arson. Journal of the Architectural Institute of Korea, 2005, 21: 235-242

[11] ISO (International Organization for Standardization). 2011. ISO 3864-1:2011. Graphical symbols – Safety colours and safety signs – Part 1: Design principles for safety signs and safety markings. Geneva: ISO.

[12] ISO (International Organization for Standardization). 2017. ISO 16069:2017. Graphical symbols – Safety signs – Safety way guidance systems (SWGS). Geneva: ISO.

[13] Jeon G-Y, Kim J-Y, Hong W-H, Augenbroe G. Evacuation performance of individuals in different visibility conditions. Building and Environment, 2011, 46: 1094-1103.

[14] Jeon G-Y, Na W-J, Hong W-H, Lee J-K. Influence of design and installation of emergency exit signs on evacuation speed. Journal of Asian Architecture and Building Engineering, 2019, 18: 104-111.

[15] Jindra LF, Zemon V. Contrast sensitivity testing: A more complete assessment of vision. Journal of Cataract & Refractive Surgery, 1989, 15: 141-148.

[16] Kinateder M, Warren WH, Schloss KB. What color are emergency exit signs? Egress behavior differs from verbal report. Applied Ergonomics, 2019, 75: 155-160.

[17] Kobes M, Helsloot I, De Vries B, Post JG, Oberijé N, Groenewegen K. Way finding during fire evacuation: An analysis of unannounced fire drills in a hotel at night. Building and Environment, 2010, 45: 537-548.

[18] Kubota, J., T. Sano, and E. Ronchi. 2024. The impact of people-signage interaction on wayfinding evacuation behaviour. Fire Safety Journal 142: Article 104023.

[19] León J, Martínez C, Inzunza S, Ogueda A, Urrutia A. Improving tsunami risk analysis by integrating spatial resolution and the population’s evacuation capacities: A case study of Cartagena, Chile. International Journal of Disaster Risk Science, 2024, 15(4): 1001-1016.

[20] Oh R-S, Kim Y-C, Bae Y-H, Choi J-H. Evaluation of the maximum cognitive distance per emergency exit sign colour in a smoke-filled environment simulated using a translucent eye patch. Fire Technology, 2023, 59: 3445-3471.

[21] Pelli DG, Bex P. Measuring contrast sensitivity. Vision Research, 2013, 90: 10-14.

[22] Shi, J., N. Ding, H. Wang, and Y. Wang. 2025. How risk preference affects evacuees’ route choice in buildings: An IVR-based experimental study. Safety Science 187: Article 106840.

[23] State Administration for Market Regulation and Standardization Administration of China. 2024. Fire emergency lighting and evacuate indicating system (GB 17945-2024). Beijing: State Administration for Market Regulation and Standardization Administration of China.

[24] Wan, Z., T. Zhou, Z. Tang, Y. Pan, and L. Zhang. 2021. Smart design for evacuation signage layout for exhibition halls in exhibition buildings based on visibility. ISPRS International Journal of Geo-Information 10: Article 806.

[25] Wang Z, Jia G. Simulation-based and risk-informed assessment of the effectiveness of tsunami evacuation routes using agent-based modeling: A case study of Seaside, Oregon. International Journal of Disaster Risk Science, 2022, 13(1): 66-86.

[26] Wang, J., L. Shen, H. Wang, R. Lovreglio, and Y. Tong. 2025. An empirical investigation on the impact of evacuation signages on individual behaviour in building evacuations. Journal of Building Engineering 111: Article 113519.

[27] Wong LT, Kwan CM. Assessing the exit sign legibility for building occupants. Architectural Science Review, 2005, 48: 153-161.

[28] Wong LT, Lo KC. Experimental study on visibility of exit signs in buildings. Building and Environment, 2007, 42: 1836-1842.

[29] Xie, C.-Z.T., Q. Chen, B. Zhu, E.W.M. Lee, T.-Q. Tang, X. Yin, Z. Yuan, and B. Zhang. 2025. Coordinating dynamic signage for evacuation guidance: A multi-agent reinforcement learning approach integrating mesoscopic crowd modeling and fire propagation. Chaos, Solitons & Fractals 194: Article 116246.

[30] Xie H, Filippidis L, Galea ER, Blackshields D, Lawrence PJ. Experimental analysis of the effectiveness of emergency signage and its implementation in evacuation simulation. Fire and Materials, 2012, 36: 367-382.

[31] Xie, W., E.W.M. Lee, Y. Cheng, M. Shi, R. Cao, and Y. Zhang. 2020. Evacuation performance of individuals and social groups under different visibility conditions: Experiments and surveys. International Journal of Disaster Risk Reduction 47: Article 101527.

[32] Yamada T, Akizuki Y. Hurley MJ, Gottuk DT, Hall JR, Harada K, Kuligowski ED, Puchovsky M, Torero JL, Watts JM, Wieczorek CJ. Visibility and human behavior in fire smoke. SFPE handbook of fire protection engineering, 2016. New York, Springer: 2181-2206.

[33] Yang Q, Dubey RK, Kalantari S. PATH-U: A data-driven agent-based wayfinding model incorporating perceived path uncertainty and cognitive strategies in unfamiliar indoor environments. Building Simulation, 2025, 18: 449-471.

[34] Yu, D., A.-M. Mahamadu, W. Chen, and N. Li. 2026. Understanding the challenges and future trends of immersive technology use in indoor pedestrian and evacuation dynamics: A systematic review. Journal of Building Engineering 121: Article 115703.

[35] Zeng Y, Song W, Jin S, Ye R, Liu X. Experimental study on walking preference during high-rise stair evacuation under different ground illuminations. Physica A: Statistical Mechanics and its Applications, 2017, 479: 26-37.

[36] Zhang, B., J.T. Lo, H. Fang, C. Xie, T. Tang, and S. Lo. 2024. Directed rooted forest based direction setting method: A step toward automated dynamic exit signs. Journal of Building Engineering 85: Article 108504.

[37] Zhang, B., Y. Yan, W. Xie, X. Luo, E.W.M. Lee, and X. Deng. 2025. The halo effect in airport terminals: How wayfinding experiences influence emergency preparedness through perceived reliability. Accident Analysis and Prevention 220: Article 108149.

[38] Zhuang Y, Wang F, Huang Y, Song X, Rao Y. Influence of guidance signs on platform evacuation in suburban railway tunnel under smoke and obstacle environment. High-Speed Railway, 2025, 3: 1-16.

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