Part I, the present paper, presents and discusses a method for the design and selection of interlocking and signaling systems which is best suited for a branching point with the associated railways to meet certain requirements with respect to operating performance and capacity. The operating conditions of the branch point are explained, including those determined by certain track arrangements with mechanical interlocks. As an example, mechanical switches and shape signals were used. Part II of the article (March issue Signal + Wire) deals with analytical models for calculating the performance characteristics of a branch point, including minimum distance, maximum speed and minimum running time of the train for a particular track configuration.