A Method of Simulation of Traffic Flow in Waterways

Abstract

The traffic capacity of a network of waterways is important for the design of a canal system in a harbor. A program for the simulation of traffic flow is studied as the first step for the evaluation of the capacity. Since the data on the traffic in the canal system of Tokyo Harbor are compiled, the simulation is applied for the Keihin Canal and its vicinity in the system, where there are curves and a T-shaped crossing. The distributions of the ship size and speed are so determined to simulate the real ones and the time of ship arrival is assumed to follow the random distribution. The unit time for the simulation is determined as 0.8τ_mean' i.e., one tenth of the time necessary to proceed 8L_mean' the semi-axis major of the evasive domain, Where L_mean is the average length of ship and τ_mean is the average characteristic time, L_mean/L_mean. When no collision, stranding, nor deep violation of center line is expected in a tim length of 8τ_mean' each ship is moved forward by 0.8τ_mean V where V is the speed of each ship. However, when a ship is expected to collide, strand, or violate the center line, the change in direction is examined and followed. If no suitable steering is expected to avoid the danger, retardation is examined. An example of the distribution of ship traces is shown as the result simulation.