A mathematical tool for road design projects

This article introduces a mathematical tool for the semi-automatic design of multiple layout alternatives for a road, and the selection, between all of them, of the most suitable option in each particular case study. This tool is based on a mathematical programming model that includes the required technical constraints to ensure safe and comfortable driving (fulfilling the current Spanish legislation) and automates the process of selecting the connecting points to the former road. This optimization module is completed by two other modules: a clustering one, that groups the layouts obtained in corridors, and a decision-making aid one, which assists the engineer in the selection of a layout alternative in each corridor and, subsequently, in the choice of the optimal overall layout. The numerical results show the usefulness of this tool in a real-life case study that consists in designing a bypass on the Spanish road N-640 that circumvents the urban area of Meira (Lugo).