Analysis of vessel traffic flow characteristics in inland restricted waterways using multi-source data

To effectively manage vessel traffic and alleviate congestion on busy inland waterways, it is crucial to understand vessel traffic flow characteristics. However, limited data availability has hindered research in this area. This study addresses this gap by conducting vessel-following experiments and fixed-point video monitoring to collect multi-source data. First, distributions of traffic flow parameters are analyzed, then the relationship between microscopic vessel speed and gap distance is examined. Next, the study explores the macroscopic relationships among speed, density, and flow rate, proposing a novel piecewise fundamental diagram model. Lastly, inland vessel traffic states are categorized using the K-means clustering algorithm, which is then applied to vessel navigation services. The results reveal that: in the inland restricted waterways of Jiangsu Province, (1) the economic speeds for empty and loaded vessels are approximately 12 km/h and 9 km/h, respectively; (2) the minimum vessel speed is around 2.65 km/h, with a minimum gap distance of 12 m; and (3) the maximum flow rate is about 44 vessels per hour, with an optimal vessel density below 4 vessels per kilometer to reduce delays and improve efficiency. These findings offer valuable insights for enhancing inland waterway transportation and supporting the development of integrated waterway systems.