Ant Colony Optimization Algorithm for Vertical Alignment of Highways

Based on discrete theory, this article tries to develop an optimization methodology to produce an optimum vertical highway profile for a pre-selected horizontal alignment. The aim of the program was to establish an initial vertical alignment according to discreet ground elevation of station. Considering the discreet characteristic of the ground elevation and the intersection point of grade line, a discrete model is presented. The automatic design problem is set to select the number, location and elevation of the intersection point of the grade line after considering several designing constraints. To solve the constrained nonlinear problem, an ant colony optimization algorithm is adopted to select the roadway grades that minimize the earthwork cost and satisfy the geometric specification. A numerical example is presented to illustrate the application of the program.