A Joint Model of Freight Mode and Shipment Size Choice

摘要

Mode and shipment size choice are among the most critical logistics decisions that despite theirstrong correlations are typically studied separately in freight demand studies. This paper employsan innovative copula-based framework to model freight mode and shipment size choicesimultaneously as a joint decision-making problem. A copula-based joint MNL-MNL model isemployed in which both mode choice and shipment size are modeled as discrete choices usingmultinomial logit structure. The intention of proposed copula-based model is to capture thepotential effects of observed and unobserved factors that jointly affect both choices. The dataused in this study were gathered through a large-scale establishment survey conducted in 2011 inthe U.S.A. The survey provided detailed information on more than 1840 individual shipmentsthat were used to develop the disaggregate models. Results of estimated model underline theimportance of inter-relationship between freight mode choice and shipment size and suggest thatthere are common influential unobserved factors that affect mode and shipment size choices. Themodel provides the ability to better capture the effects of observed and unobserved factors thataffect both choices simultaneously.