محمدحسام شجاع خواه

The increasing growth of e-commerce an‎d the increase in the volume of postal items in Tehran have intensified the pressure on the road transport network, resulting in consequences such as increased traffic congestion, reduced transportation speed, an‎d increased fuel consumption an‎d pollutants. In this study, with the aim of investigating the efficiency of the underground logistics system based on the metro in transporting postal shipments, a combination of system dynamics simulation an‎d discrete event simulation was used to eva‎luate the urban impacts an‎d operational performance of this system in different scenarios. The results of the system dynamics model showed that the use of the metro network capacity caused a continuous an‎d gradual increase in the average speed of the ground fleet, so that in different operational scenarios, an increase in speed of about 1 to 2.5 percent was observed. Also, the use of the metro during non-working hours an‎d its combination with working hours caused a significant reduction in the delivery time of packages; so that, depending on the level of operation, the delivery time was reduced by about 11 to 18 percent an‎d more sustainability was created in the distribution process. The environmental impacts were also significant; The results showed that with the increase in the share of freight movement by the metro, the emission of particulate matter decreased significantly an‎d reached practically zero at the highest level of use. The fuel consumption of the ground fleet also decreased significantly in the scenarios based on the use of the metro an‎d its increasing trend stopped. In the analysis of discrete event scenarios, a significant difference was also observed between working an‎d non-working hours. Activity during non-working hours reduced the unloading time at the stations an‎d prevented congestion at the destination station. Also, in multi-station distribution scenarios, instead of completely unloading the cargo at the last station, the total unloading time was reduced by about 20-30%, which indicates the importance of choosing the appropriate loading an‎d unloading pattern. Overall, the results of this study indicate that the establishment of a metro-based underground logistics system can be proposed as a practical an‎d sustainable solution for freight transportation management in Tehran by significantly reducing delivery time, reducing pollutant emissions, reducing fuel consumption, an‎d improving the performance of the ground fleet. This system, using existing metro infrastructure an‎d without the need to develop heavy infrastructure, creates significant capacity to improve urban logistics an‎d can be an important step towards moving towards a smart, clean, an‎d efficient transportation system.

سيستم لجستيك زيرزميني , سيستم لجستيك زيرزميني مبتني بر مترو , سيستم لجستيك شهري , شبيه‌سازي سيستم لجستيك زيرزميني مبتني بر مترو

Underground logistics system , metro-based underground logistics system , urban logistics system , metro-based underground logistics system simulation

Mohammad Hesam Shojakhah

Dr.Morteza Bagheri