Research On Time Window Assignment Pollution Routing Optimization Considering Time-varying Traffic Congestion

In recent years,urban logistics has developed rapidly,driven by the expansion of the e-commerce industry.The total cost of social logistics has increased year by year,and transportation costs constitute an important part of the total social logistics.Studies have shown that the large amount of carbon dioxide generated in logistics transportation,is one of the main sources of carbon emissions;The process of urbanization has gradually accelerated,the car ownership has increased,the logistics distribution network has become increasingly complex,the resulting traffic congestion has also led to the emission of large amounts of carbon dioxide,and environmental pollution has become increasingly serious.Therefore,it is of great practical significance and long-term planning to consider traffic congestion and vehicle emissions in terms of urban logistics and distribution,which will not only help alleviate urban traffic and improve travel capabilities,but also reduce carbon emissions and achieve environmental protection.In the logistics distribution process,it is equally important to maintain a long-term cooperative relationship with customers.Distribution at a fixed time,for customers and logistics companies,can effectively manage inventory and reasonable personnel arrangements;reduce the variability of distribution,improve distribution efficiency,and save costs.For this reason,based on the distribution environment of time-varying traffic congestion,the problem of time windows assigning pollution routing is studied.It reviews the current status of research problems and their development trends by documenting pollution routing problems,time-varying vehicle routing problems,and time window assignment vehicle routing problems.Firstly,the pollution routing problem considering time-varying traffic congestion is studied.the influence of vehicle routing optimization on carbon emission in time-varying congestion is studied,the waiting strategy of vehicle on the driving arc is introduced,and the two-objective optimization model with minimum carbon emission and minimum travel time is established.An improved tabu search algorithm is designed.Then,use a simulation example.The applicability of the model and the effectiveness of the algorithm are verified.Secondly,the time window assignment pollution routing problem with time-varying traffic congestion is studied.Logistics companies need to assign a time window to customers before the start of distribution.Due to the characteristics of time-varying traffic congestion and customers with uncertain demand before distribution,the concept of demand scenarios is introduced based on the waiting strategy.A two-objective optimization model with minimum cost(carbon emission cost and travel cost)and minimum delivery time is established.Considering the complexity of the model,A hybrid genetic-tabu search algorithm is designed using the global search advantages of the genetic algorithm and the local search advantages of the tabu search algorithm.Through the analysis of algorithm performance,the effectiveness of the hybrid genetic-taboo search algorithm is verified.Finally,taking Chongqing Chongbai Supermarket as an example,a case study is made on the problem of assigning pollution routing to time windows of time-varying traffic congestion in urban distribution.The results show that the problems studied in this paper can effectively reduce carbon emission costs and travel costs,but will cause an increase in delivery time.Through the comparison of different goals,the effectiveness of the mutual balance between delivery time and carbon emissions is analyzed.Compared with unwaitable on the arc results,arc waiting can reduce the carbon emissions by5.9617%,but increase driving time by 4.6095%,It shows that the vehicle waiting strategy proposed in this paper is conducive to improving carbon emissions.To some extent,the impact of traffic congestion on distribution is reduced.