Estimate travel time of ships in narrow channel based on AIS data

Abstract

This paper proposes an AIS-data-based model to accurately estimate vessels' travel time and its distribution between any two points in a narrow channel. It is crucial to know the travel time (plus its distribution) between some critical points for traffic control. The model has two components: (1) to identify a vessel's destination dock, and its arrival and departure times (the key is how to separate a vessel's trips); and (2) to estimate a vessel's travel time from its destination dock (or a specific point) to another specific point, or vice versa. Travel time between two points is called traversal time. The proposed algorithms were then applied to the Houston Ship Channel (HSC) with the AIS data of 11 months in 2017, focusing on the outbound trips in the section above the Beltway-8 Bridge. Through the travel times of cargos and tankers from their destination docks to a point are likely to be normally distributed, their traversal times between two points are more likely to be lognormally distributed. The traversal time distribution is significantly impacted by vessel width, draft and type, but independent from time-of-day and month. The adjacent link traversal times are also highly positively correlated.