Concurrent optimization of mountain railway alignment and station locations using a distance transform algorithm

Railway location design is a complex and time-consuming task in which the intricate interactions among railway alignment and station locations must be considered. However, most optimization methods emphasize either alignment optimization or station locations optimization while ignoring the coupling constraints for railway alignment and station locations. In addition, these methods are mainly applied to plain areas with relatively simple topographies and often fail to find feasible altematives in complex mountainous areas. This paper proposes a concurrent optimization method for railway alignment and station locations. Coupling constraints for railway alignment and station locations are formulated and addressed, and station locations are generated while searching the railway alignment. The method can be applied for more general terrains, including complex mountainous areas. The effectiveness of the method is verified through a real-world case study in a complex mountainous area. The results show that the proposed method can concurrently find the optimal railway alignment and station locations for specific objectives and multiple constraints and provide various promising alternatives.