Dezhi Zhanga , Xialian Lia, ShuangyanLib, Qi Qiana
a School of Traffic & Transportation Engineering, Central South University,Changsha Hunan, 410075, China
bSchool of Transportation and Logistics,Central South University of Forestry and Technology, Changsha Hunan, 410004,China
Abstract. This paper proposes a model to address the design problem of a regional logistics network. In the proposed model, the decision variables include the location and size of logistics parks. The interaction between the logistics authority and logistics users as well as the effects of economies of scale and CO2emission taxes on the logistics network design are explicitly considered. The proposed model is formulated as a bi-level formulation, in which the upper level aims to maximize total social welfare of the system by determining the optimal location and size of logistics parks with CO2emission taxesconsideration, whereas the lower level describes the logistics users’ choices for service routes. A heuristic solution algorithm is presented to solve the proposed model, and a numerical example is given to illustrate the applications of the proposed model and solution algorithm. The findings show that the optimal location and size of logistics parks depend on the realized logistics demand and the level of the economies of scale. The CO2 emission taxation can help to improve the total social welfare of the system and drive the logistics users to choose greener transportation modes.
Keywords:Regional logistics network,bi-level model,logistics parks,CO2emission taxes,economies of scale.
1. Introduction
Environmental issues have recently attracted considerable public attention around the world. There is a wide consensus that freight transportation is a major contributor to climate change and global warming is due to various pollution emissions. It has been shown that freight transportation contributes to about 5.5% of global greenhouse gas emissions(McKinnon, 2010). The report on CO2emissions in 25 European countries during 1990-2005 also indicated that about 26% of total CO2emissions in the air come from transportation. During logistics service activities, the CO2emissions from transportation amounts to 93% of total pollution emissions, while the warehousing only covers 7% (Decker, 2011). It is, therefore, very important and urgent to create an environmentally sustainable logistics system.
Green logistics focuses on improvement of logistics service efficiency, decrease in logistics cost, and reduction in environmental externalities (e.g. CO2) so as to achieve a sustainable balance among economic, environmental and social objectives(Dekker et al., 2012; McKinnon et al., 2012). Aronsson and Brodin (2006)showed that logistics efficiency and cost were not only related to the structure of supply chains, but also the logistics network design and logistics infrastructure. As an important component of a regional logistics system (or urban logistics system), logistics network design is a strategic issue, involving logistics facility planning and sustainable logistics management policy-making (Beškovnik and Twrdy, 2012; Lindholm and Behrends, 2012).
Various logistics centres have recently been established in large cities for quickly distributing freight. However, this raises many important issues, such as traffic congestion, air pollution and high energy consumption. To efficiently cope with these issues, it is proposed to combine multiple logistics centres into a logistics park. A logistics park, which is also referred to as “logistics village” in Germany, “distribution park” in Japan, and “logistics platform” in Spain, is a specially important component of the regional logistics network. A logistics park implies a spatial concentration area for grouping various activities, such as transportation, distribution, warehousing, commercial trade, and other related services (such as maintenance and repair). It is also an intersection of different transport modes, and an interface between local traffic and long-distance traffic(Rodrigue et al., 2009; Wagener, 2008).