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1
The Incorporation of Layout Design into an
Agent-based Evacuation Model
Tariq M. Elhassani, Jun Zhang, Mahmoud T. Khasawneh, and Ra’ed M. Jaradat

to simulate the interactions between the three elements.
Abstract—The innovative designs and layouts of buildings and
public places have created a major issue in evacuating a massive
group of people under intense and panic situations. In this paper,
we developed an agent-based model to investigate the effect of
layout design, people, and nature of threat on emergency
evacuation. The purpose of this research was to provide a
preliminary attempt at using agent-based modeling and
simulation analysis to explore potential options that people have
when faced with bomb explosion in an open market Environment.
The results show that evacuation time, number of fatalities, and
number of injuries are influenced by the layout design
components, namely locations of rescue area, check point, and the
bomb itself.
Index Terms—Agent-based modeling, bomb explosion,
emergency evacuation, layout design, marketplace, rescue
operation.
I. INTRODUCTION
T
HE ongoing trend of advanced knowledge in building
designs and structures has raised major concerns for
people safety. Innovative methods and approaches are needed
to understand and assess these complex designs to assure
people safety and verify compliance with standards and
guidelines. Traditionally, verification has been demonstrated
through full-scale evacuation drills and practices. A promising
alternative to assess people safety lie's in computer evacuation
models. The development of evacuation models in the last
three decades has mainly contributed to the assessment of
people safety and evacuation procedures in a variety of
designs, under a range of environmental conditions. The
effectiveness of such evaluation relies mainly on the models’
ability to reflect the detailed interactions between the
occupant, building design, and environment. The evacuation
models not only evaluate the efficiency of evacuation
processes by controlling challenges presented in evacuation
drills, but also simulate the dynamic interaction between the
structure, people, and the environment. The purpose of this
paper is to model the influence of structure layout, people
behavior, and environmental conditions on the emergency
evacuation process. An agent-based model has been developed
T. M. Elhassani, J. Zhang, M. T. Khasawneh, and R. M. Jaradat are all
graduate students in the Department of Engineering Management and
Systems Engineering at Old Dominion University, Norfolk, VA 23529 USA
(corresponding author’s phone : 757-683-5145; fax: 757-683-5640; e-mail:
[email protected])..
II. LITERATURE REVIEW AND BACKGROUND
Agent Based modeling (ABM) is classified as a
computational model that simulates the actions and
interactions of multiple autonomous decision-making entities
[1]. Agent-based modeling, sometimes called individualoriented, or distributed artificial intelligence-based, is an
increasingly powerful modeling technique for simulating
individual interactions in a dynamic system and is distinctive
in its ability to simulate the situation where the future is
unpredictable [2]. ABM is used to develop models for a
population dynamics system and a segregation system [1]. In
the last few years, agent-based modeling has emerged in
social, political, and economic science applications [3].
Agent-based modeling has played a key role in modeling
human behavior and performance in emergency evacuations
applications. Henein and White have proposed an efficient
based model of crowd evacuation that incorporates pushing
forces and injuries [4]. Their model was an enhancement of the
pre-existing Kirchner model [5], and it investigates the force
effects at different crowd densities [4]. Shendarkar,
Vasudevan, Suengho, and Son have used virtual reality (BDI)
to construct crowd simulation and demonstrate the use of the
same for crowd evacuation management under terrorist bomb
attacks in public areas [6]. The study was conducted to
explore the crowd behavior under an evacuation situation in
the event of a terror attack at the National Mall area in
Washington DC [6]. The results obtained from this
experiment gave an explicit insight into the patterns of human
thought processes. Chen study aims to investigate the
effectiveness of simultaneous and staged evacuation strategies
in different road network structures by using ABM simulation
[7]. The study was able to model the traffic flow at the level
of individual vehicles in this case agents during an evacuation
in natural way [7]. The results showed how the evacuation
time changes in different flow modes.
III. PROBLEM DESCRIPTION AND MODELING
A. Problem Description
Emergency evacuation is the urgent movement of people
from dangerous place due to the threat or occurrence of a
disastrous event [8]. Human life is always threatened by many
hazards such as bombs, fires, explosions, and toxics. The
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innovative designs and layouts of buildings and public places
have created a major issue in evacuating a massive group of
people under intense and panic situations. A mass movement
of a crowd under panic can easily lead to injuries or deaths, if
the crowd fails to run away from the hazardous area. In this
paper, we developed an agent-based model to investigate the
effect of layout design, people, and nature of threat on
emergency evacuation. Our model represents an open market
place under a bomb threat. It consists of a set number of
shoppers and security officers placed randomly in the market,
a bomb threat, a shelter place, and a check point. In addition to
evacuation time, the model captures other output variables
such as the number of fatalities and injuries, number of people
who seek shelter at the public shelter place, and number of
people who run toward the check point.
B. Problem Modeling
NetLogo is a cross-platform multi-agent programmable
modeling environment [9]. NetLogo is one of the most used
software in agent-based modeling simulation; it was originally
developed in 1999 by Uri Wilensky, a professor of Learning
Sciences and Computer Science at Northwestern University
[10]. NetLogo is very simple software that enables one to
understand the concept of agent-based modeling. NetLogo
was initially used for educational purposes but later many
researchers have found it a very easy and useful tool to learn
and to conduct profound research.
The proposed evacuation model in this paper shows the
effect of layout design, people, and nature of threat on
emergency evacuation. Our NetLogo, agent-based model
(presented in Fig. 1) represents an open market place under
bomb threats. It consists of agents (population), bomb
(hazard), shelter, and check point. The inputs to the model
include
 The location (coordinates) of the rescue area (white color).
 The location (coordinates) of the bomb threat.
 The displacement of the people (blue color).
 The displacement (locations) of security officers (orange
color).
 The location (coordinates) of the check point.
The location of the rescue area is assigned randomly. The
purpose of that is to observe and study the relationship
between its locations and the output variables. The rescue area
is located anywhere in the model except the impact area of the
bomb. There is no full capacity for the rescue area. When the
bomb explodes, people who are closed to the rescue area will
run to it.
The location, impact and the explosion time of the bomb
can be changed manually using the slide bars. The bombimpact ranges from 1 to 40. For the purpose of the study, we
set the bomb-time at 10 ticks for all simulation runs. The bomb
time indicates the time between the start of a simulation run
and when the bomb explodes to guarantee the random
movement of people in the marketplace.
2
The people in the model move in a random heading. There
is no specific pattern or algorithm for the movement of people
before the bomb goes off. Such setting makes the model more
realistic to the problem at hand. Once the bomb goes off,
people will move in the opposite direction from the bomb
impact towards either the rescue area or the boundaries of the
marketplace. Only the people who are in the rescue area’s
influence distance will run away toward it. Otherwise they will
evacuate to the boundaries. The influence distance, set at 14,
identifies how close people are to the rescue area. It ranges
from 0 to 20. There is no collusion between people during the
evacuation. If the people trapped inside the bomb-impact zone,
they will either die or injured. The “population” slide bar was
used to change the number of the people. The number of the
people ranges from 1 to 300. In all the runs we set the number
at 150.
Fig. 1. Snapshot of NetLogo before bomb deploys.
The officers will also move in a random heading. Their
primary task is to rescue the injured people once the bomb
explodes. Accordingly, the code has been programmed to let
the officers who are closed to the bomb-impact zone to run
directly to rescue injures. The other officers who do not rescue
the injured will not move (stop). The number of officers could
range from 1 to 30. In this simulation we made sure that there
is one officer for each injured person.
The last input to the model is the location of the check
point. It functions as a rescue area for the injured people. The
non injured people will never escape to the check point. The
location for the check point is fixed with all runs. We created a
monitor to calculate the number of the injured in the check
point.
The evacuation time in this model starts once the bomb goes
off until all injured people arrive at the check point.
Evacuation time is calculated as
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3
TABLE II
ET = T – BT
(1)
 ET: evacuation time
 T : ticks count
 BT: bomb time. The time before the bomb goes off.
this case 10
We assumed this market is an open one. So we didn’t have
any obstacles (other buildings) in this system.
STATISTICAL DESCRIPTIVE OF OUTPUT VARIABLES
Output
Variables
Standard
Deviation
Mean
Minimum
Maximum
ND
8.1
2.8
2
17
NI
7.9
2.7
1
14
NR
22.6
6.8
1
41
ET
122.8
12.1
91
151
ND = number of deaths, NI = number of injuries, NR = number in
rescue area, ET = evacuation time.
IV. ANALYSIS AND DISCUSSION
The purpose of this research is to provide a preliminary
attempt at using agent-based modeling to investigate the
impact of structural layout, people behavior, and
environmental conditions on the evacuation of people from a
marketplace. In order to investigate the effect of such elements
on evacuation, a set of input variables were loaded to the
NetLogo model (Table 1). The model was run a total of 300
simulation runs. In every run, both the location of shoppers
and the rescue area have been changed. Fig. 2 illustrates a
snapshot of a simulation run during the evacuation process.
Table 2 summarizes the statistical descriptive of the output
variables in relation with the location of the rescue area.
Since the location (coordinates) of the rescue area has been
randomly changed at every simulation run, it is essential to
further investigate the impact of such locations on the output
variables, namely evacuation time, number of deaths, number
of injured, and number of shoppers who run to the rescue area.
Figures 3-6 depict the surface plots for the rescue area
locations and the output variables.
TABLE I
15
MODEL INPUT VARIABLES
Input Variables
Values / Coordinates
Population
150
Security officers
20
Bomb impact
12
Bomb location (x, y)
(-19, 17)
Bomb time
10
Check point location (x, y)
(0, 35)
Run to rescue area distance
14
ND = number of deaths, NI = number of injuries, NR = number in
rescue area, ET = evacuation time.
ND
10
5
0
-40
20
-20
0
0
X
Y
-20
20
-40
Fig. 3. Number of Deaths as a function of applied field.
15
NI
10
5
0
20
-40
0
-20
0
X
20
-20
-40
Fig. 4. Number of Injuries a function of applied field.
Fig. 2. Snapshot of Netlogo after the bomb deployed.
Y
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on people safety. Further, since any layout design (structure)
TABLE III
OUTPUT VARIABLES FOR DIFFERENT LOCATIONS
Output
Variables
ND
NI
NR
ET
45
30
NR
15
0
-40
L1
(-35, -21)
2*
12
14**
136
Output
Variables
-20
L2
(34, 30)
17**
9
19
132
L5
(2, -8)
L3
(20, 10)
6
1*
36
119
L6
(28, -17)
L7
(25, -17)
L4
(-33, -19)
7
14
13
134
L8
(17, -18)
20
0
ND
NI
NR
ET
0
X
20
Y
-20
-40
Fig. 5. Number in Rescue Area.
9
5
1*
98
2*
10
41**
141
10
4
26
91*
15
13
31
151**
ND = number of deaths, NI = number of injuries, NR = number in
rescue area, ET = evacuation time.
must provide protection to the people to reach safety, future
research can be conducted to investigate the optimal location
of such design components to minimize evacuation time and
number of deaths and injuries. Finally, the deterioration of
environmental conditions, level of uncertainty, stress, and the
interaction of people with such factors influence the adoption
of new responses. Such responses can be incorporated into
advanced versions of the proposed agent-based model.
160
140
ET
120
100
-40
0
0
X
ACKNOWLEDGMENT
20
-20
-20
20
Y
-40
Fig. 6. Evacuation Time a function of applied field.
The authors would like to thank Drs. Rani A. Kady
([email protected]) and Andreas Tolk ([email protected]), both
with the department of Engineering Management and Systems
Engineering, for their guidance and support throughout the
study.
REFERENCES
V. CONCLUSION
The purpose of this research was to provide a preliminary
attempt at using agent-based modeling and simulation analysis
to explore potential options that people have when faced with
bomb explosion in an open market Environment. The
developed model demonstrates the significant role agent-based
modeling plays to capture accurate and representative details
of the evacuation process at the agent (evacuee) level. Further,
the results show that evacuation time, number of fatalities, and
number of injuries are influenced by the layout design
components, namely locations of rescue area, check point, and
the bomb itself. Table 3 lists a range of statistical output
measures for four different selected locations.
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VI. FUTURE RESEARCH
The developed model can be used in future research to
investigate allocating necessary resources such as ambulances,
hospitals, shelters to minimize the impact of bomb explosions
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