2013 Session: 671

• Optimization Model for Dispatching Heterogeneous Emergency Vehicles
  Abstract: An emergency is a situation that causes an immediate risk to the property, health, or lives of civilians. Emergency response services such as police, fire, and medical services play crucial roles in all communities and can minimize the adverse effects of emergency incidents by decreasing the response time. The goal of this research is to develop a comprehensive optimization dispatching model for emergency call centers or emergency management centers. This model can come up with the best dispatching algorithm based on real-time information about the status of the emergency-response fleet, traffic information and the status of emergency calls. This problem is formulated as an integer programming model. Three categories of emergency vehicle types are considered in the system: police cars, ambulances, and fire vehicles. The police department is assumed to have a homogeneous fleet, but ambulances and fire vehicles are heterogeneous.
  Authors: Sharifi, Elham; Haghani, Ali; Sadrsadat, Hadi
  Authors: Sharifi, Elham; Haghani, Ali; Sadrsadat, Hadi
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-0686
• ON TRAFFIC SAFETY HAZARDS IN EVACUATIONS DUE TO CHANGES IN DRIVING BEHAVIOR
  Abstract: Real-life observations as well as driving simulator experiments have shown how driving behavior under mentally demanding conditions, such as during an evacuation, differs in certain aspects from that at normal traffic conditions. In this paper, we continue with these findings by investigating how these differences in driving behavior have an impact on traffic safety. For this, the microscopic simulation framework S-Paramics is adapted accordingly, and applied to the evacuation network of the Dutch city of Almere. This experimental setup allows a structured and in-depth analysis of the relationship between a number of driving behavior parameters and the emergent traffic safety, which are quantified by four different safety indicators based on the well-reported time-to-collision value. Where earlier studies conclude that a reduction in mean time headway and minimum gap acceptance substantially improves the overall evacuation time, here it is found to also result in more traffic safety hazards, potentially leading to actual traffic accidents that in turn may obstruct the evacuation progress. Furthermore, traffic safety is shown to decline over time, resulting in (substantially) less safe conditions for those who depart later. With these model results and findings, the accompanying discussions and conclusions are insightful and have direct implications for evacuation planning and control practices.
  Authors: Tu, Huizhao; Li, Hao; Pel, Adam J.; Sun, LiJun
  Authors: Tu, Huizhao; Li, Hao; Pel, Adam J.; Sun, LiJun
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-1124
• Bilevel Model for Optimal Shelter Selection in Emergency Evacuation Operations
  Abstract: Due to the frequent happening of catastrophic natural disasters and man-made disasters in recent decades, emergency management has become an important issue around the world. Therefore, effective traffic operations for emergency evacuation during emergency events are critical to alleviate the impact from disasters. Designing well-planned evacuation routes is the first priority for the evacuation process. Before planning the evacuation routes, the evacuation demand patterns for different areas in different disaster scenarios must be known. Moreover, the shelter locations are the basis for us to plan for evacuation routes. This research proposes a bi-level programming model to combine the shelter location problem and the evacuation trip distribution problem. The shelter location problem is formulated as a mathematical model solved by the CPLEX optimizer in the upper level. The evacuation trip distribution problem is solved by an entropy-based gravity model and the DynaTAIWAN simulation assignment model in the lower level. The upper level aims to determine the location of shelters selected, while the lower level aims to determine the trip distribution from the result of shelter location problem. The results from the proposed model determine the locations of shelter and the total number of shelters. This research suggests the Kaohsiung City Government should setup “regular shelter” and prepare emergency kits (survival kits) and emergency relief (goods or materials in emergency) at the regular shelters for the sake of emergency conditions.
  Authors: Hu, Ta-Yin; Ou, Hui-Ching; Ho, Wei-Ming
  Authors: Hu, Ta-Yin; Ou, Hui-Ching; Ho, Wei-Ming
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-1929
• Calibration and Validation of a Regional-Level Traffic Model for Hurricane Evacuation
  Abstract: One of the key issues with evacuation models, or any traffic model, is that some public officials place little faith in the results generated by these models. The way to reassure doubts is by thorough calibration and validation of the model. However, there has been little research in this particular area of evacuation modeling. In an effort to expand the literature on evacuation model calibration/validation, the purpose of this paper is to provide a narrative in which the authors discuss the calibrated and validated a regional-scale evacuation model using observed evacuation data. A traffic simulation model was developed to analyze traffic conditions associated with a regional-level mass emergency evacuation for Southeastern Louisiana. The model was constructed using the TRANSIMS transportation modeling system. The narrative details three important aspects of traffic modeling: trip assignment convergence, macro-level calibration, and network flow validation. Similar results were found after testing two convergence criteria sets. A “descending” criteria set was ultimately chosen since it could lead to a more robust routing solution. During the calibration procedure, it was difficult to determine which parameter value would be the most appropriate. This was an expected result since the calibration focused on the entire regional network rather than select routes. The validation procedure revealed the importance of including background traffic in the simulation model. The results here should lead to further enhancements made toward effectively calibrating and validating traffic models for evacuation analysis.
  Authors: Montz, Thomas; Zhang, Zhao
  Authors: Montz, Thomas; Zhang, Zhao
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2339
• Evacuation in Large-scale Transportation Network: A Bi-Level Control Method with Uncertain Arterial Demand
  Abstract: To improve the efficiency of large-scale evacuation, a network aggregation method and a bi-level optimization control method are proposed in this paper. The network aggregation method indicates the uncertain evacuation demand on the arterial sub-network and balances accuracy and efficiency by refining the local road sub-networks. The bi-level optimization control method is developed to reconfigure the aggregated network from both supply and demand sides with contraflow and conflict elimination. The main purpose of this control method is to make the arterial sub-network to be served without congestion and interruption. Then, a corresponding bi-objective network flow model is presented in a static manner for an oversaturated network, and a GA-based solution method is used to solve the evacuation model. The numerical results from optimizing a city-scale evacuation network for a super typhoon justify the validness and usefulness of the network aggregation method and optimization control method.
  Authors: Hua, Jingyi; Ren, Gang; Cheng, Yang; Yu, Chen; Ran, Bin
  Authors: Hua, Jingyi; Ren, Gang; Cheng, Yang; Yu, Chen; Ran, Bin
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2254
• Generalized Minimum Cost Flow Model for Multiple Emergency Flow Routing and Optimal Contraflow Design
  Abstract: During real-life disasters, such as earthquakes, floods, terrorist attack and other unexpected events, emergency evacuation and rescue are two main operations to save affected people¡¯s life and property. It is unavoidable that evacuation flow and rescue flow will conflict with each other on the same spatial road network and in the same time window. We proposed a generalized minimum cost flow model to optimize the distribution pattern of these two kinds of flow on the same network by introducing the conflict cost. The travel time on each link is assumed to be subject to BPR function rather than a fixed cost (such as link length or free flow travel time). Also, we integrate contra-flow operations into this model to re-design the shared network by those two kinds of flow. Consequently, a non-convex mixed integer non-linear programming model with bilinear, fractional and power items is constructed. GAMS/BARON is used to solve this programming model, and a case study is performed in downtown area of Harbin city in China to verify the efficiency of proposed model. Several helpful findings and managerial insights are also presented.
  Authors: An, Shi; Cui, Jianxun; Wang, Jian; Zhao, Meng
  Authors: An, Shi; Cui, Jianxun; Wang, Jian; Zhao, Meng
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2438
• Considering Individuals with Disabilities in Building Evacuation: Agent-Based Simulation Study
  Abstract: Catastrophic events in the United States have highlighted numerous issues regarding effective emergency evacuations. In existing studies, individuals with disabilities have not been a significant feature of evacuation investigations due to the lack of empirical data and thus their evacuation needs have been generally overlooked. The purpose of this paper is to evaluate how effectively the built environmental accommodates the needs of individuals with disabilities during emergency evacuations. Specifically, we explored whether there is a difference between the general population and population with considering individuals with disabilities in terms of time to egress via an agent-based microsimulation called BUMMPEE model. This model can consider several types of disabilities explicitly in terms of speed, ability to negotiate the environment, and psychological profile depending on type of disability. The model was applied for a real four story office building. The results of simulation experiments show that there is a significant difference between mean evacuation time for homogenous and heterogeneous populations. An increase in population size leads to an increased difference. Additionally, results demonstrate that the fourth floor of the building has the worst performance among other floors and persons who use wheelchairs are most at risk during emergency evacuation process.
  Authors: Christensen, Keith; Sharifi, Mohammad Sadra; Chen, Anthony
  Authors: Christensen, Keith; Sharifi, Mohammad Sadra; Chen, Anthony
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2790
• Understanding Evacuation Destination Distance and Departure Time Choices: Joint Modeling Approach
  Abstract: This paper investigates the causal factors that influence the household-level evacuation departure timing and the destination distance choices under two different behavioral assumptions, namely the decisions are made simultaneously or sequentially with the evacuation timing determined after the destination. The effects of various independent variables are compared using the bivariate Generalized Linear Model (BGLM) and Poisson model. Under either assumption, the number of children under 17 and pre-evacuation preparation time are statistically significant. More children under 17 increase the likelihood of leaving early. Less time in pre-evacuation preparation leads to a later departure. The Poisson model with random parameters also found statistical significance for the household size and partial regional difference for evacuation timing choice. In the BGLM model, evacuation accommodation type, household income, and education level are statistically significant for evacuation timing. The travel distance depends on many factors. Public shelter as the destination, the number of elderly people, no evacuation warning, low income and shorter preparation time contribute to a shorter travel distance. A large household size, a mandatory evacuation recommendation, and post-graduate education level lead to longer travel distance. In order to examine the behavior of the households under the no-evacuation warning situation, a random-coefficient model is used to capture the possible behavioral heterogeneity among the underlying evacuation population under the sequential decision-making assumption. The departure time decisions for the “shadow evacuation” population are not statistically different from those who received an evacuation warning, but among the “shadow evacuation” population itself, departure timing shows heterogeneity.
  Authors: Yin, Weihao; Murray-Tuite, Pamela; Ukkusuri, Satish V.; Gladwin, Hugh
  Authors: Yin, Weihao; Murray-Tuite, Pamela; Ukkusuri, Satish V.; Gladwin, Hugh
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2935
• Optimal Planning of Signal Control and Uninterrupted Flow Strategies in a Dynamic Evacuation Network
  Abstract: It is well accepted in literature that uninterrupted flow (or cross-elimination) operations can significantly outperform signal control strategies in terms of expanding network capacity and improving the overall evacuation performance. This result holds well in a static network in which the dynamic flow patterns are not explicitly modeled (e.g., queuing on network links and time-varying evacuation demand). This paper examines the problem of planning signal control and uninterrupted flow strategies in a dynamic evacuation network setting. More specifically, the following critical questions are investigated: 1) Do the findings from previous studies regarding the uninterrupted flow operations still hold in a dynamic evacuation network? 2) Does an optimal trade-off between signalized and uninterrupted flow operations exist to maximize the overall evacuation performance? 3) If yes in 2), what would be their most appropriate numbers and locations? And 4) How to set turning restriction plans for those uninterrupted flow intersections?
  Authors: Liu, Yue; Luo, Zhenke; Yu, Jie; Mao, Jing
  Authors: Liu, Yue; Luo, Zhenke; Yu, Jie; Mao, Jing
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-3279
• How to Evacuate? Model to Understand Routing Strategies During Hurricane Evacuation
  Abstract: In this paper we explain a modeling approach which offers better understanding of the routing strategies taken by the evacuees to reach a safe destination during hurricane evacuation. Route choice during evacuation is a complex process, because evacuees may prefer to take the usual or familiar route on the way to the destination or they might follow the routes recommended by the emergency officials. Depending on the condition of the traffic stream, sometimes they might switch to a different route to obtain better travel time from the one initially attempted. By using data from Hurricane Ivan, a mixed (random parameters) logit model is estimated which captures the decision making process on what type of route to select while accounting for the existence of unobserved heterogeneity across households. Estimation findings indicate that the choices of evacuation routing strategy involve a complex interaction of variables related to household location, evacuation characteristics and socio-economic characteristics. The findings of this study are useful to determine different fractions of people in selecting a type of route for a given socio-demographic profile during an evacuation.
  Authors: Sadri, Arif Mohaimin; Ukkusuri, Satish V.; Murray-Tuite, Pamela; Gladwin, Hugh
  Authors: Sadri, Arif Mohaimin; Ukkusuri, Satish V.; Murray-Tuite, Pamela; Gladwin, Hugh
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-3642
• Optimal Traffic Routing for Large-Scale Evacuation in Urban Networks with Various Threat Levels
  Abstract: This paper investigates a traffic network evacuation model with non-uniform threat levels, minimizing an objective of total exposure (duration and severity) to the threat among all vehicles. The model is essentially a min-cost dynamic flow problem associated with time-dependent arc costs. The traffic flow models included in this representation are the point queue and the spatial queue models. The evacuation model is solved to optimality on a time-expanded network using commercial software. The model and associated solution method are applied to solve a large-scale chlorine release scenario in Tucson, Arizona.
  Authors: Nassir, Neema; Zheng, Hong; Hickman, Mark D.; Chiu, Yi-Chang
  Authors: Nassir, Neema; Zheng, Hong; Hickman, Mark D.; Chiu, Yi-Chang
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-4174
• Calibration and Validation of a Regional-Level Traffic Model for Hurricane Evacuation
  Authors: Montz, Thomas
  Authors: Montz, Thomas
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2339
• Considering Individuals with Disabilities in Building Evacuation: Agent-Based Simulation Study
  Authors: Christensen, Keith
  Authors: Christensen, Keith
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2790
• Optimization Model for Dispatching Heterogeneous Emergency Vehicles
  Authors: Sharifi, Elham
  Authors: Sharifi, Elham
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-0686
• Considering Individuals with Disabilities in Building Evacuation: Agent-Based Simulation Study
  Authors: Chen, Anthony
  Authors: Chen, Anthony
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-2790
• Optimal Traffic Routing for Large-Scale Evacuation in Urban Networks with Various Threat Levels
  Authors: Nassir, Neema
  Authors: Nassir, Neema
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management; Safety and Human Factors; Security and Emergencies
  Session: 671
  Paper Number: 13-4174