Research On Freight Mode Choice Behavior Model Considering Inertia Effect

One of the important tasks to support the low-carbon transformation of the overall transport system is optimizing and adjusting the structure of freight transport modes and accelerate the promotion of shifting freight from road to rail.Accurate grasp of the characteristics of the transport market demand,the design of railway freight products in line with market demand is the key to promote the freight modal shift from road to rail,which requires an accurate grasp of the shipper way to choose the behavior of the mechanism.The existing freight mode choice behavior model focuses on the study of the influencing factors of transportation service attributes,and lacks the consideration of the choice inertia of shipper,which leads to the "distortion" of shippers’ behavior analysis and the "inaccuracy" of demand analysis,and it is difficult to accurately evaluate the potential of freight modal shift from road to rail.Based on this,this paper takes container transportation as the research object,focuses on the research of shippers’ freight mode selection behavior,concentrate on the selection inertia effect of freight modal shift from road to rail,analyses the influence mechanism of selection inertia on freight mode selection behavior,and discusses the difference of inertia effect among different demand characteristic groups.Furthermore,the freight mode selection model considering inertia effect is used to analyze the elasticity of transport service attributes,the shipper’s willingness to pay analysis and the transport mode sharing rate simulation,so as to explore the influence of inertia effect on the demand prediction of the model.The research results are expected to provide theoretical reference for the government management department to formulate and optimize the guidance policy of "freight modal shift from road to rail".Provide reference for railway transport enterprises to design differentiated freight service products according to different demand characteristics.The specific work and main conclusions are as follows:Firstly,the base model(defined as M1),which does not consider inertia variables,and three models(defined as M2,M3 and M4),which consider different inertia measures,are constructed.By comparing the fit of M1-M4 to the sample data,it is found that the model that includes the inertia effect has a higher goodness of fit to the sample data,indicating that the shipper has a significant inertia effect in choosing the mode of transport.Furthermore,by comparing the M2,M3 and M4 models,it is found that the model(M2)which takes the form of0-1 variable to measure the inertia effect has better performance in terms of data fitting effect and rationality of behavior interpretation,indicating that the inertia effect of highway shippers is mainly related to their past selection results.Secondly,the optimal inertia variable index,transport service attribute variable and non-transport service attribute variable are selected to build a freight mode selection behavior model with linear utility(defined as M5),and the inertia effect of "freight modal shift from road to rail" is analyzed as a whole.The results show that the inertia resistance of "freight modal shift from road" is large,and the estimated value of the inertia effect is 0.8724,which is 39 times the marginal utility of transport time(or cost).On this basis,an interaction term model(defined as M6)was constructed considering the selection of inertia variables and transport service attributes,and the influence mechanism of inertia variables was analyzed.The results show that under the influence of selection inertia,the shipper underestimates the cost level of road and overestimates the "door-to-door" transport time of rail,which is an important reason for the high inertia resistance of "freight modal shift from road to rail".Furthermore,an interaction term model(defined as M7)was constructed,taking into account the selection of inertia variables and different demand characteristic groups,to explore the differences in the inertia effects of different transport demand characteristics.The results show that there are significant differences in the inertia effect between different demand groups.In the existing road transport market,freight forwarders,heavy and medium/long distance consignments show weak inertia effect in the choice of freight mode,which is an important target for railway transport companies to explore the "freight modal shift from road to rail" freight source.Finally,the model is applied to analyze the elasticity of transport service attributes,shippers’ willingness to pay and mode sharing rate simulation,and the influence of the inertia effect on the model’s demand prediction is explored.The results show that ignoring inertia leads to an underestimation of time elasticity and an overestimation of cost elasticity.In terms of willingness to pay,it will underestimate shippers’ willingness to pay for transport time.There are significant differences in the willingness to pay for transport time between different demand groups.In the current freight market,the willingness to pay is relatively high for cargo owners,light bubble goods and short-distance transport.The simulation results of the railway sharing rate show that reducing the railway transport time and cost and increasing the road transport cost can effectively increase the railway market share.