Modeling emergency evacuation of individuals with disabilities (exitus): An agent-based public decision support system Matthew Manley a,⇑ , Yong Seog Kim b a Utah State University, Logan, UT 84322-3515, USA b Utah State University, Logan, UT 84332-3515, USA article info Keywords: Public decision support system Agent-based modeling Pedestrian simulation Emergency evacuation Individuals with disabilities abstract In this paper, we present a public decision support system (DSS) distinguished from various DSSs in the private business sector in terms of its ownership, data scarcity, and beneficiaries. In particular, our sys- tem is intended to play a vital role in assessing and optimizing emergency response plans for rare but catastrophic events such as the September 11th attacks. While taking an agent-based microscopic simu- lation approach in a hierarchical framework, we used our model to estimate the effectiveness of alterna- tive evacuation strategies to support emergency response planning as a part of business continuity planning for all private business organizations. The presented model is unique because it considers indi- viduals with disabilities explicitly in terms of speed, ability to negotiate the environment, and normalcy bias depending on type of disability. It is also capable of classifying the environment in terms of acces- sibility characteristics encompassing various conditions which have been shown to have a disproportion- ate effect upon the behavior of individuals with disabilities during an emergency. Through a series of simulation experiments, our system identified specific locations (e.g., the NW land- ing) on the 3rd floor of the test bed building as possible bottleneck spots under certain conditions (e.g., the sharp increase in individuals with disabilities among residents). This way, our system provides the architect with tools to test the structure’s design to determine how well it meets the identified require- ments for emergency evacuation to accommodate this shifting demographic. In particular, our system strongly demonstrated the effectiveness of new emergency evacuation strategies for individuals with dis- abilities such as assisted evacuations which allows other healthy people to play more active roles com- pared to traditional strategies in which individuals with disabilities are helplessly waiting for assistants such as fire fighters at the designated area. Our system also revealed that people using wheelchairs and those with lower stamina were at the greatest risk. People with lower stamina such as the elderly, people with chronic health conditions, or those with temporary injuries are at a greater risk mainly because they are not easily identifiable. Ultimately, the proposed DSS system can be used to inform public policy pro- fessionals of more effective, evidence-based evacuation planning and environmental design methods based on a better understanding of the behavior of individuals with disabilities. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Decision support systems (DSS) which facilitate business conti- nuity planning (BCP) are important for private business entities which are inordinately affected by large scale catastrophic events (Chen, 2006). Consider that almost 18,000 businesses were dislo- cated, disrupted or destroyed as a result of the terrorist attacks on September 11, 2001 (Makinen, 2002), and nearly 104,000 busi- nesses were similarly affected as a result of Hurricane Katrina (Burton & Hicks, 2005). Many of the establishments affected by these kind of events never reopen and a portion of those which do often go out of business shortly thereafter. Note that emergency preparedness and response is designated as one of the six critical mission areas in the ‘‘National Strategy for Homeland Security’’ report (Office of Homeland Security, 2002). Due to the nature of these events, a key objective of BCP for private entities should be efficiently evacuating workers, customers, and visitors to ensure the return to normal business operations as soon as possible. While the need for such DSSs are well recognized, they present a particular challenge for small and medium-sized businesses in that development requires rigorous theoretical and predictive analytics as well as a deep understanding of the complexity of the social dynamics involved. Even if large firms have sufficient financial and human resources to implement such a system, they may be disinclined to do so because of the system’s public nature 0957-4174/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.eswa.2012.01.169 ⇑ Corresponding author. E-mail addresses: matthew.t.manley@aggiemail.usu.edu (M. Manley), yong.kim@usu.edu (Y.S. Kim). Expert Systems with Applications 39 (2012) 8300–8311 Contents lists available at SciVerse ScienceDirect Expert Systems with Applications journal homepage: www.elsevier.com/locate/eswa