A Study On Carbon Reduction In The Vehicle Routing Problem With Simultaneous Pickups And Deliveries

Reducing greenhouse gases especially carbon dioxide has become theworld’s hot issue. Ranking second in cargo turnover volume in our country,road cargo transport has become China’s key industrial field of carbon dioxideemissions. How to calculate the carbon dioxide emissions in the road cargotransport and considering reducing carbon dioxide emissions in the vehiclerouting problem are both of the essence. The vehicle routing problem withsimultaneous pickups and deliveries (VRPSPD) is a common type of road cargotransport problems, and get more and more popular with the environmentalprotection consciousness get year by year strengthen. The calculation methodof carbon dioxide emissions in road cargo transport and low carbon research inVRPSPD problem are both introduced in this paper.When to calculate the carbon dioxide emissions in road cargo transport,the right account unit should firstly be selected according to the transportationservice type, and then the calculating boundary, specific critical processes anduncritical processes are determined according to different specific requirements.Secondly, according to the specific accuracy requirements and cost limits, thedata should be collected for each specific process. Finally, the right calculationmethod and carbon dioxide emissions allocation method should be used foreach specific process, and then the total carbon dioxide emissions of the roadcargo transport service is gotten.Afterwards this paper uses a2-index directed commodity flow model tomodel the VRPSPD problem which considers reducing carbon dioxideemissions. In this model, only two main influences of carbon dioxide emissionsfrom vehicles are taken: the vehicle load and driving distance. Via setting theparameters, the objective of this model can be the shortest driving distance, theminimum carbon dioxide emissions, or the lowest total cost. And the total costincludes driving distance related cost, fuel cost, carbon dioxide emissions environmental costs and setup cost of vehicles.The case study in this paper concluded that the model with the minimumcarbon emissions objective or the lowest total cost objective is able to generateroutes with lower total cost, less carbon emissions and not much longer totaltravel distance than the model with the shortest path objective. Moreover, inrespect to low carbon emissions, the advantage of the model with the minimumcarbon emissions objective will be more significant when the fuel consumptionof vehicles without load could decrease in the further, the mean value ofdistance between nodes is bigger, or the scale of distance between nodes issmaller. Finally, this paper presents several suggestions about capturing vehicleroutes with low carbon dioxide emissions and total cost. These suggestions canhelp the dispatcher to capture vehicle routes without any software.