Decision Support Systems for Real-World High-Speed Rail Planning

Abstract

The selection of the macrolocation of new high-speed rail (HSR) systems during the planning stage affects the associated infrastructure costs. The process is influenced by the complex interaction between the HSR alignment, the technical solutions, and the characteristics of the deployment site, subject to layout restrictions. Decision support systems for the optimization of the HSR alignment are developed for addressing the requirements of large and complex real projects. The formulation includes costs, geometric constraints, connection requirements, and consideration of natural barriers such as protected land use and bodies of water, ubiquitous in real projects. The simulated annealing algorithm is implemented to address challenges of real problems and solve the optimization model. The approach is applied to a Portuguese HSR case. The solution obtained optimizes its alignment by minimizing the construction costs, consistent with existing projects worldwide, and complying with location, geometry, and land-use restrictions. The approach is not case specific and can be used to systematically study trade-off opportunities and support decision making in similar planning problems. Alternative solutions can be generated based on different judgments on the trade-offs.