Study On Routing Optimization For Multi-modal Hazardous Materials Transportation

Nowadays,the logistics industry has become a new industry of sustainable development,and the logistics system is constantly improving.In the whole logistics system,the logistics of hazardous materials is gradually growing.But hazardous materials manufacturing enterprises are mostly away from the urban area because of its particularity.According to statistics,nearly 95%of the hazardous materials in our country need remote transportation,and annual transportation volume up to 200 million tons.In the process of transportation,the routes are constrained doubly by the transport operator and the government.The purpose of the transport operator is to maximize revenue,and minimize the cost when to select the route;but on the other hand,in the process of transportation,hazardous materials poses a threat to the surrounding environment,so the government can not ignore the route of the carrier selection,need to assess its risk,as far as possible to minimize the harm.These two hands belongs to the contradiction relationship.So it needs to be studied,and to find a path which can meet the goal of low cost carriers and can meet the requirements of the government to minimize the risk.Hazardous materials transportation modes have two forms:unitary transportation and multi-modal transportation.For the local area transportation,you can use a mode of transportation.But during the long distance transportation,the transport operator often use multi-modal transportation.Multi-modal transportation refers to combined transportation of a variety of transport modes in order to achieve the goal of optimization of transportation.First of all,the study current situation of routing optimization for hazardous materials transportation at home and abroad was detailed analyzed.Combing the relevant theory,comparing the model and algorithm,finding out the problems and shortcomings were summarized.Then,the research was improved according to the corresponding shortcoming,and the problem on routing optimization of multi-modal hazardous materials transportation in dynamic network was studied.Because cost and risk are changing with time in the actual transportation,so the time needs to be divided into phases and cost and risk need to be quantified.This paper construct a model of routing optimization for multi-modal hazardous materials transportation in time varies situation and design Dijkstra improved algorithm.Based on this,we combine the distribution center location problem with multi-modal transportation.In order to reduce the complexity of the research,this paper do not consider the time variability of cost and risk and construct a model of the problem on distribution center location-routing optimization for multi-modal hazardous materials transportation.By introducing the target weight and the factor of economic transformation,the bi-level objective programming model is transformed into the single objective programming model.The paper use the improved Dijkstra algorithm to solve multi-modal transportation routing optimization.In addition,design the O-D matrix search algorithm to solve the optimization grouping problem of distribution center and the demand points.Finally,through a small scale transportation network,according to the known transportation data,the model and algorithm are verified effective and reasonable.