Transportation Research Part C: Emerging Technologies
A decision support system for integrated hazardous materials routing and emergency response decisions
Introduction
Hazardous materials transportation constitutes a significant economic activity involving annual cargo which exceeds 2 billion tons in USA. The total cargo had risen 20% over the period 1997–2002 (USA Census Bureau, 2002) and transportation by truck accounts for 52.9% of this quantity. The highway accidents account for 89% of the total hazardous materials serious incidents involving release or fatalities and the associated total annual damages are estimated to be approximately 31 million dollars ($80,000 per incident) (USA DOT, 2003). Despite the fact that hazardous materials accidents are rare events (10−8–10−6 per vehicle-mile) (Erkut and Verter, 1995, Zografos and Davis, 1989), the potential adverse consequences raise serious concerns to all stakeholders involved in or affected by the hazardous materials transportation. These stakeholders include the state, public authorities, shippers, carriers, local societies and social groups exposed to risk. In this context, the mitigation of transportation risk, i.e., expected consequences of an accident, constitutes a major goal for all stakeholders involved in hazardous materials transportation.
Hazardous materials routing is recognized as a critical decision in mitigating risk (Erkut et al., 2007). In particular, hazardous materials transportation risk may be drastically reduced by planning routes that minimize the probability of an accident, restrain the potential consequences and secure the timely and unobstructed provision of the emergency response services. Substantial research has been focused on developing mathematical models and applications for determining safe and economical hazardous materials routes. A major feature of the previous related work pertains to the development of mathematical models that address the problem of routing hazardous materials shipments ignoring the proximity of the routes from the emergency response services. Moreover, the existing work on hazardous materials routing is ultimately concentrated on analysing and solving the path finding problem that minimizes cost and/or risk related criteria. No application has been documented in the area of hazardous materials distribution decisions. Finally, no application has been identified that assesses the potential evacuation implications of alternative hazardous materials routes.
This paper presents a GIS-based decision support system (DSS) that aims to fill the above gaps in the literature by addressing the following types of hazardous materials transportation and emergency response logistical decisions:
- 1.
Determination of the hazardous materials distribution routes in terms of cost and risk minimization. This problem arises during the planning phase of the delivery process of hazardous materials carriers.
- 2.
Optimum deployment of the first-response emergency service units. This type of decision is confronted by the actor(s) involved in the management of the hazardous materials emergency response system.
The proposed system is also enhanced with an evacuation tool that aims to facilitate the evacuation planning process through providing evacuation paths in case of a hazardous materials accident on any of the distribution routes. This type of problem is encountered by the actor(s) responsible for the coordination and management of the relevant evacuation process.
The proposed system constitutes an integrated platform for assessing alternative route choices in terms of transportation cost, risk, the relevant emergency response services proximity and potential evacuation implications. The system has been implemented and evaluated within the area of Thriasion Pedion of Attica in Greece, a heavily industrialised area with high frequency of hazardous materials shipments.
The objective of the paper is to provide an exposition of the above stated logistical problems, the associated solution methods, and the major functionalities of the system. A new mathematical model is proposed for the hazardous materials routing problem while a new algorithm is presented for solving the first-response emergency service units location problem. The paper also discusses the implementation of the proposed system in Thriasion Pedion describing the context of this application and an illustrative case study highlighting the potential use of the system under real-world conditions.
The remainder of this paper consists of four sections. Section 2 presents the previous related mathematical models and applications supporting hazardous materials logistical decisions. Section 3 provides a concise description of the aforementioned routing and emergency response planning problems and an overview of the proposed solution methods. Section 4 presents an overview of the modules and functionalities of the proposed decision support system and provides a case study in Thriasion Pedion. Finally, Section 5 provides the concluding remarks of the presented research work.
Section snippets
Previous related work
Hazardous materials transportation decisions have attracted substantial research attention over the past two decades. The major part of this research activity has been placed on the development of mathematical models and applications for the selection of safe and economical hazardous materials routes. Two major routing problems have been studied: (i) identification of optimum paths between an origin and destination from the perspective of a single carrier/shipper and (ii) specification of the
Risk assessment
A major task of this study relates to the assessment of alternative hazardous materials routes in terms of risk. Several risk measures are confronted in the relevant literature, e.g., population exposure (Batta and Chiu, 1988), incident probability (Saccomanno and Chan, 1985), perceived risk (Abkowitz et al., 1990) and expected disutility (Erkut and Ingolfsson, 2000). The present research has adopted the traditional risk measure given by the following equation:where πij is the
System design and functionalities
The development of the proposed system followed the classical five stages of a DSS life cycle including user requirements analysis, functional specifications, system design, prototype development and evaluation. The specification of the user requirements was based on a national survey of the actors involved in the hazardous materials transportation and emergency response management, i.e., emergency service providers, hazardous materials customers, carriers, public authorities and policy makers.
Concluding remarks
This paper has presented an integrated DSS for routing hazardous materials and locating first-response mobile units within a specified coverage time from the hazardous materials routes. The implementation of the proposed system requires the consent of the shippers/carriers and the emergency response actors for sharing private information. Under this perspective, the proposed system has been implemented and evaluated for covering the hazardous materials distribution within the area of Thriasion
Acknowledgements
The research reported in this paper has been partially supported by the Greek General Secretariat of Science and Technology under the contract “Development of an Integrated Decision Support System for Hazardous Materials Management” (SDEF-23).
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