Optimization model of short-distance liner ship route based on tripartite game

Government subsidy, carbon emission control, shippers' choices of transport modes were considered, the optimization model of short-distance liner ship route was developed based on tripartite game relations among carriers, shippers and government. The model could not only optimize the fleet deployment and structure design of ship route simultaneously, but also work out the reasonable amount of government subsidy by using user equilibrium principle. A genetic algorithm based on time-space network expansion and Frank-Wolf algorithm was developed to solve the model, and short-distance liner ship routes in the western area of Bohai Bay were optimized. Analysis result shows that when pendulum-pattern route among major ports in the western area of Bohai Bay is deployed with 9 ro-ro ships of 40 000 t, and government subsidy is 1 121.28 yuan · d^-1, the total benefit of per ship is 704 567.12 yuan· d^-1, carbon emission reduces by about 17.78%. When carbon emission is expected to decrease by more than 20%, circle-pattern route is deployed with 8 ro-ro ships of 40 000 t, the route can bring total benefit of 956 264.83 yuan · d^-1 for carriers, reduce carbon emission by about 27.23%, but government subsidy reaches up to 56 075.26 yuan· d^-1. The calculating result accords with the expectation result, so the optimization model is effective.