Routing of Trains between Parallel Railway Lines

The main technical stations and lines involved in routing of trains can be viewed as nodes and directional arcs. As the train routing can be determined exclusively by the array of the directional arcs or nodes, the essence of the problem is to make choice from the directional arcs among neighboring nodes to another line. Considering the line resources occupied by trains and the influence of division plan on operating quality of trains, we set up the appraisal criterion on trains operation adjustment and traveling speed, and build the optimization model which aims at the integrated optimization of running cost, traveling speed and daily adjustment of trains. This model is characterized by large scale, multiple objectives, multiple stages, nonlinearity and combination optimization, with relatively high complexity. Using the satisfying optimization theory, we manage to transform the operation adjustment and traveling speed into restrictions by selecting proper astricted values, and then, turn the model into a single-object programming one. Researches indicate that deciding the astricted values is equal to feeding back the practising effect. Accordingly, we could divide the optimizing process into two steps: to ascertain feasible and better schemes and to evaluate and ameliorate the forenamed schemes in terms of traveling speed and operation adjustment. Based on those mentioned above, general procedures are put forward to solve this optimization problem. Applied in Beijing-Jining Section of Jinglan corridor, this method is proved to be valid and feasible.