Optimization of ship transport capacity structure for traffic congestion alleviation on inland waterways

Due to constraints of ship locks, the increasing demand for cargo transportation across the lock will continue to exacerbate vessel congestion in the Three Gorges Dam reservoir area, severely hindering the high-quality development of Yangtze River shipping. Considering that the dimensions of the ship locks cannot be altered, this paper proposes a method for optimizing the ship transport capacity structure (STCS) of inland waterway to alleviate ship traffic congestion in the Three Gorges Dam reservoir area. Firstly, based on the cargo transportation network extracted from OD data, the demand for goods transportation is calculated. Secondly, a multiobjective optimization model for optimizing STCS is designed, and the optimal STCS is determined by combining traffic flow simulation models, ship lock layout optimization models, gradient descent strategies and ant colony algorithms. Then, a model for evaluating ship traffic congestion is constructed to quantify the level of ship traffic congestion. Finally, combined with cargo transport OD (origin-destination) data, simulation-based comparative experiments are conducted to validate the effectiveness of the proposed model in alleviating traffic congestion and increasing transportation capacity. The findings of this research hold crucial implications for high-quality traffic management of ships navigating the Yangtze River.