Optimization of express distribution by cooperatively using private trucks and buses

For dealing with the demand of large quantity, small parcel, high batch frequency, and high timeliness of urban express distribution, the distribution mode by cooperatively using buses and private trucks was proposed, and an optimization model aimed at minimizing the total cost of express distribution was built.The transport network of expresses based on cooperatively using private trucks and buses was optimized by determining distribution batches, departure time and distribution routes.Ant colony algorithm was designed for solving model.The schemes of collaborative distribution and sparate distribution only using trucks were solved and compared for97 demand sites based on the road network and public transit network in Dalian.Analysis result shows that, in collaborative distribution mode, the total cost decreases by 9.5%, the driving distance of trucks decreases by 12.6%, the CO₂ emission decreases from 0.159 tto 0.139 t, the demand sites of unpunctual distribution decreases by 26.2%, and the total delay decreases by57.7%.In additional, the applicative range of unit time penalty cost of collaborative distribution is 0.2-0.4 yuan·min^-1, and the optimal unit distribution cost of buses is 1.5 yuan· (t·km) ^-1.In conclusion, the collaborative distribution can provide better service than truck distributionbecause of lower distribution cost, higher punctuality and less environmental load in certain extent.