Modelling An Improved Ship Appointment System for Lockage Operations of Waterway Transport

Abstract

The traffic congestion problem has become a significant challenge for green shipping of inland waterway transport, resulting in long waiting times and high carbon emissions. Several studies have been conducted to optimize the use of the passing facilities and lockage efficiency, but the improvement of the ship appointment system has not been investigated. In this paper, we formulate new mathematical models for an improved appointment system to manage the ship arrival pattern. With a better matching between the ship arrivals and the lockage capacity, both average waiting time and carbon emissions can be reduced. To achieve this goal, a new nonlinear bi-objective optimization model is formulated to balance the waiting time and the scheduling adjustment. The bisection method with point-wise stationary fluid flow approximation (B-PSFFA) is used to estimate the ship arrivals and calculate the ship waiting time and the associated carbon emissions. The numerical results of a real-world case study at the Three Gorges Dam illustrate that optimizing the appointment quota can effectively adjust the ship arrivals to relieve the waterway transport congestion and reduce carbon emissions. In addition, the number of appointment segments divided within the planning horizon has an impact on the scheduling decisions.