Research On Container Drop And Pull Vehicle Scheduling Problem In Collection And Distribution Of Port

Drop and pull transport mode is an advanced transportation organization which has been widely recognized and applied in the international. Compared with traditional transportation modes, it has an advantage in improving tractor utilization, reducing the waiting time of loading and unloading time, improving the productivity of road transport, saving the cost of business operations, and so on. Although the country has always been to increase efforts to promote drop and pull transport, but its promotion in China faces many problems. In the field of academic research, domestic scholars focused on macro issues, such as the policies and advantages to develop drop and pull transport. Less scholars focused on the drop and pull transport specific applications, especially in port container transport vehicle scheduling problems. So it has important practical significance to do research on specific applications of drop and pull transport in the port container transport.Firstfly, this paper does a comprehensive analysis of the mode’s operation and operating procedures in port container transportation. And then the vehicle scheduling theory, which is related to the port container transport, is studied.Secondly, container import and export freight tasks are broken down into the cargo subtasks. Taking subtasks as research subjects, this paper establishes the non-timewindow vehicle scheduling model of drop and pull transport mode. The recovery and delivery problem of empty containers and chassics is considered in the vehicle scheduling model. And The mathematical model is solved successfully by improved greedy algorithm.In addition, the characteristic of customer’s service time of the drop and pull transport system is analyzed. Based on the existing multi-timewindows vehicle routing problem, the multi-timewindows problem in drop and pull transport is transformed into single time window problem successfully. And then this paper establishes the drop and pull transport mode vehicle scheduling model with timewindow by taking subtasks as research subjects. Satisfactory solution of this model is achieved by the improved greedy algorithm.Lastly, the advantages of drop and pull transport mode in the utilization of vehicle, transport efficiency and fleet operating costs are verified based on the real production data of Rongqi port in Foshan. The example analysis proves the economic advantage of drop and pull transport mode. Compared with the traditional mode, if the enterprise complete the same amount of import and export transportation business through drop and pull transport mode, the number of tractors and trailers can be reduced by61.5%and12.4%. Although the annual fuel costs rise, the reduced number of tractor ultimately saves a total operation cost of2.404million yuan, a decrease of39.9%. If we further consider labor costs, the benefits will be even more impressive.