Traffic flow in the crossing points is the important factor for the traffic capacity as well as the safety of navigation. In order to remove the dangerous encounter of the ships, the authors studied the time sheared traffic control at the crossing points highlighted on the parallel route crossings (Fig. 1). Digital simulation were made to evaluate the effectiveness of the control system, the distance for time adjustment (DA) and the distance between the crossings (DC) are the controlling factors of the system. Two control system were considered in this paper, one is the priority in order of arrival (first come first service system), the other is signal system. Whether a ship is able to adjust the time or not is decided by its characteristics of the speed control. Minimum time control theory was employed as a base index of this adjustable time. The major conclusion obtained are; (1) The distance for the time adjustment relate with the uniformalizing of the arrival time at the crossing point. Increasing from 10, 000m to 20, 000m, the rate of the unallocatable ships are decreased 1020%. (2) Longer distance between the No. 1 and No. 2 crossing point reduces the interference between the crossing points. In the signal system, the signal interval is dependent on the distance. Increasing the distance, the degree of freedom in the sellectting the signal interval become greater. (3) In the priority system in order of arrival, 210 vessels/day are able to pass the crossing under the condition of DA=10, 000 m, DC=3, 000 m. Signal system has the greater capacity of 300 vessels/day if DA≥20, 000m.