An Agent-Based Dynamic Framework for Population Evacuation Management

Abstract

Evacuating the population during crises to safe zones via optimal paths is vital. The evacuation planning process makes two main decisions: which shelter to reach and which path to take towards the chosen shelter. These decisions correspond to shelter allocation and traffic assignment problems, respectively. Many studies tackled these problems with a static formulation in the literature, while only a few considered a dynamic context. We conduct a comprehensive literature review and highlight that most studies independently solve these two problems while both are correlated with traffic conditions. To fill this gap, we propose a new framework to couple the shelter allocation problem (SAP) and the dynamic traffic assignment (DTA) problem and solve them. To capture traffic dynamics, we use a dynamic agentbased simulator. We assume the system determines the evacuees' shelters to minimize the total evacuation time. However, each evacuee's concern is reaching a shelter as fast as possible. Therefore, we formulate the DTA problem under stochastic user equilibrium (SUE) principles, i.e., every evacuee aims to minimize his own perceived travel time. We apply the proposed methodology to the network of Luxembourg City and compare its performance with other advanced methods that solve SAP and DTA separately. The comparison shows that solving the dynamic shelter allocation improves the mean evacuation time and significantly decreases the network clearance time compared to other methods with a fixed plan for SAP. The simulation results prove that considering the network state in the SAP can provide a more effective evacuation plan. Moreover, we perform a sensitivity analysis on optimization parameters and evaluate the computation cost of our methodology.

Smart dynamic evacuation planning and online management using vehicular communication system

“…The proposed methodology of this study follows a sequential process, consisting of two main phases: the initial planning phase and the online evacuation management phase. The initial planning phase adopts the methodology used in Idoudi et al (2022a) to provide the initial plan. However, the planning model is modified for SUE instead of a pure UE solution.…”

“…In Step 2 (initial evacuation plan), the initial evacuation plan is established, leveraging multilevel DTA and static assignment problem, taking into account SO and SUE conditions. The methodology used in this step is detailed in Idoudi et al (2022a). The "Plan" Phase commences with Step 3 (simulation of the current time step and set t = t+1).…”

“…The initial planning phase adopts the methodology used in Idoudi et al. (2022a) to provide the initial plan. However, the planning model is modified for SUE instead of a pure UE solution.…”

“…Hsu and Peeta (2014) considered the evacuation planning process, including the DTA problem with a fixed shelter allocation schema. The previous study of the authors (Idoudi et al., 2022a) tackled both dynamic problems sequentially, minimizing the total travel time in SAP and calculating UE for DTA. However, this work did not consider telecommunication networks.…”

“…In contrast, the simulation phase involves simulating the vehicles along their designated routes, which are determined by the output of the optimization process. The model used to assign users to the route is the C‐logit mechanism (Idoudi et al., 2022a) that satisfied the SUE conditions at the convergence. All the models mentioned above are defined in the planning phase and used to create the initial plan for evacuees.…”