An Integrated Contraflow Strategy for Multimodal Evacuation

To improve the efficiency of multimodal evacuation, a network aggregation method and an integrated contraflow strategy are proposed in this paper. The network aggregation method indicates the uncertain evacuation demand on the arterial subnetwork and balances accuracy and efficiency by refining the local road subnetworks. The integrated contraflow strategy contains three arterial configurations: noncontraflow to shorten the strategy setup time, full-lane contraflow to maximize the evacuation network capacity, and bus contraflow to realize the transit cycle operation. The application of this strategy takes two steps to provide transit priority during evacuation: solve the transit-based evacuation problem with a minimum-cost flow model, firstly, and then address the auto-based evacuation problem with a bilevel network flow model. The numerical results from optimizing an evacuation network for a super typhoon justify the validness and usefulness of the network aggregation method and the integrated contraflow strategy

Maximum Contraflow Evacuation Planning Problems On Multi-network

Contraflow approach for the evacuation planning problem increases outbound capacity of the evacuation routes by the reversal of anti-parallel arcs, if such arcs exist. The existing literature focuses on network contraflow problems that allow only anti-parallel arcs with equal transit time. However, the problems modeled on multi-network, allowing parallel as well as anti-parallel arcs with not necessarily equal transit time, seem more realistic. In this paper, we study the maximum dynamic contraflow problem for multi-network and propose efficient solution techniques to them with discrete as well as continuous time settings. We also extend the results to solve earliest version of the problem for two terminal series parallel (TTSP) multi-network

Evacuation Planning Based on the Contraflow Technique With Consideration of Evacuation Priorities and Traffic Setup Time

Evacuation planning with the contraflow technique is a complex planning problem. The problem is further complicated when more realistic situations such as evacuation priorities and the setup time for the contraflow operation are considered. Such a complex problem has yet to be discussed in the present literature. In this paper, we present a multipleobjective optimization model for this problem and a two-layer algorithm to solve this model. Experiments on three transportation networks with different network scales are presented to show the excellent performance of the proposed model and algorithm.published_or_final_versio

On Evacuation Planning Optimization Problems from Transit-based Perspective

Increasing number of complex traffic networks and disasters today has brought difficulty in managing the rush hours traffic as well as the large events in urban areas. The optimal use of the vehicles and their assignments to the appropriate shelters from the disastrous zones are highly complicated in emergency situations. The maximum efficiency and effectiveness of the evacuation planning can be achieved by the appropriate and significant assignment of the transit dependent vehicles during pre and post-disaster operations. This paper presents a comprehensive overview of the evacuation planning optimization techniques developed over the years, emphasizing the importance of their formulation and the solution strategies on disaster management from the transit-based perspective. Each technique is briefly described and presented lucidly with some of its known applications, significances, and solution strategies expecting that it should be able to guide much more interest into this important and growing area of research

A Generalized Minimum Cost Flow Model for Multiple Emergency Flow Routing

During real-life disasters, that is, earthquakes, floods, terrorist attacks, and other unexpected events, emergency evacuation and rescue are two primary operations that can save the lives and property of the affected population. It is unavoidable that evacuation flow and rescue flow will conflict with each other on the same spatial road network and within the same time window. Therefore, we propose a novel generalized minimum cost flow model to optimize the distribution pattern of these two types of flow on the same network by introducing the conflict cost. The travel time on each link is assumed to be subject to a bureau of public road (BPR) function rather than a fixed cost. Additionally, we integrate contraflow operations into this model to redesign the network shared by those two types of flow. A nonconvex mixed-integer nonlinear programming model with bilinear, fractional, and power components is constructed, and GAMS/BARON is used to solve this programming model. A case study is conducted in the downtown area of Harbin city in China to verify the efficiency of proposed model, and several helpful findings and managerial insights are also presented

Mass Evacuation Effects on Transportation: A Comparative Analysis

Mass evacuations have changed greatly in the past two decades. Evacuations such as Louisiana during Hurricane Katrina, Florida during Hurricane Irma, and New York during the 9/11 Terrorist Attacks, Hurricane Sandy, and Hurricane Irene have had significant impacts on future mass evacuations in terms of transportation. This paper takes these methods and analyzes the best approach in given situations based on volume capacity, impact, and cost to make recommendations that can be used by the three previously mention municipalities. With so many different techniques available, it is important to choose the one that moves the most people out of harm’s way as quickly and effectively as possible while still being economical. Data from various transportation engineering professionals is used to examine different techniques. Many of these papers have been published by Transportation Research Board. Additionally, a subject matter expert interview was conducted with Dr. Scott Parr, Ph.D. from Embry-Riddle Aeronautical University. Based on the research conducted, Emergency Shoulder Usage (ESU) is a superior option to contraflow. Fee suspension also has a significant impact on areas with a low-income area. In areas where there was a switch from pretimed signal timing to semi-actuated or fully actuated signal timing a better LOS during mass evacuations was seen. For the implementation of these techniques to be beneficial, resiliency is important and why the last recommendation calls for professionals to petition for better infrastructure and resiliency. Based on the research conducted, Emergency Shoulder Usage (ESU) is a superior option to contraflow. Fee suspension also has a significant impact on areas with a low-income area. In areas where there was a switch from pretimed signal timing to semi-actuated or fully actuated signal timing a better LOS during mass evacuations was seen. For the implementation of these techniques to be beneficial, resiliency is important and why the last recommendation calls for professionals to petition for better infrastructure and resiliency

EVACUATION ROUTE MODELING AND PLANNING WITH GENERAL PURPOSE GPU COMPUTING

This work introduces a bilevel, stochastic optimization problem aimed at robust, regional evacuation network design and shelter location under uncertain hazards. A regional planner, acting as a Stackelberg leader, chooses among evacuation-route contraflow operation and shelter location to minimize the expected risk exposure to evacuees. Evacuees then seek an equilibrium with respect to risk exposure in the lower level. An example network is solved exactly with a strategy that takes advantage of a fast, low-memory, equilibrium algorithm and general purpose computing on graphical processing units