Container Drop And Pull Vehicle Routing Problem In A Hub And Spoke Network

Drop and pull transportation is a transport arrangement strategy in which tractor deliberately drops the trailer at the goods working spot, hook on other trailers and continually drive on as planned operations. Drop and pull transportation collectively involves techniques of car transport, train transport and loading-discharging, which makes an intensive and efficient transport arrangement mode. It enjoys apparent advantage in increasing transport efficiency, reducing logistic costs, cutting down energy consumption, etc. Drop and pull has been a highly developed and advanced transport arrangement strategy in developed countries and emerging industrialized economy.Recently China has only witnessed an initial development in Drop and pull transportation. Firstly, small total number of tractors and trailers, and small tractor trailer ratio; secondly, road goods transport dominated by van; thirdly, energy conservation and green gas emission status quo collided with the requirement of modern logistics. In China concerning Authority emphasize the importance of drop and pull transport. In 2009, Ministry of Transportation and other ministries officially published <On promoting the development of Drop-and-Pull Transports, which symbolize the launch of the next batch of drop and pull transport pilot projects.Extension line centralized-sparse drop and pull transportation could serve inland trunk container transport system, taking full advantage of drop and pull transportation and improving the transporting efficiency of container freight network. However, drop and pull has characteristics of multiple schedule objects and extension network has characteristic of hub-spoke, which adds up to the difficulty in container trunk drop-and-pull transport. So as to fill up the margin of drop and pull transportation in the industrial dispatch theory and promote the healthy and stable development of Chinese container drop-and-pull transport property, this research aims at developing systematic theory on optimization of drop-and-pull transport arrangement, providing scientific instructions on industrial practices, and making key progress in solving current urgent issues in transport.This thesis explains the concept of drop-and-pull transport, arrangement mode, and state-of-art at overseas and abroad. Then based on the industrial common practices, the author of this thesis analyze the actual operation of container drop-and-pull transport, set up non-empty container sharing container drop-and-pull transport cart arrangement model with shortest path hub-spoke network.Through further analyzing the methods of space optimization, the author put forward hub-spoke network container drop-and-pull transport empty container sharing operation mode, then simulate cart arrangement issue and solve for optimization answers. A series of simulation experiments have been conducted, in which analysis results help carrying out sensitivity analysis on key parameters and verify the validation of proposed algorithm. In the end, two different operation modes, namely empty container share operation mode and non-empty container share operation mode, have been compared, certifying the former is superior to the latter.