The application of ship maneuvering simulations in the evaluation of restricted channels that are required to accommodate two-way traffic is described in this paper. The application is illustrated by results from actual studies of the Baltimore channels carried out to validate channel reductions from 800 to 700 ft and from 1,000 to 800 ft, respectively, and an increase of the water depth from 45 to 50 ft to allow ships with deeper draft and larger tonnage to call at Baltimore. Initial studies were conducted using two coupled ship-handling simulators, each conned by a separate pilot and crew in communication and visual contact with the other ship. This initial study covered meeting situations for two-way traffic in the Craighill Angle channels. The data from these simulations provided the meeting situation strategies used by the pilots. Based on these strategies, a traffic ship control system was developed for use in later phases of the program. In all meeting situations, both ships are described with full hydrodynamic models. The later phases of the program involved simulation studies of the Brewerton channels, Rappahannock Channel, and York Spit channels. These studies consisted of fast-time simulations in which both own ship and traffic ship were computer controlled, and real-time simulations in which the own ship was controlled by a pilot and the traffic ship was computer controlled. A rule-based traffic ship control system was developed to control both ships in fast-time simulations and the traffic ship in real-time simulations.