Finding the Vertical Alignment of Forest Roads Using Several Heuristic Techniques

Once the horizontal alignment of a forest road section between two known locations has been determined by establishing a series of intersection points, the most economic vertical alignment can be identified using heuristic techniques. In a previous research work, Simulated Annealing (SA) was used to locate the optimal vertical alignment for a preselected horizontal alignment, while subject to the geometric design specifications, environmental requirements, and driver safety. The feasible vertical alignments were generated by adjusting the intersection points using a neighborhood search procedure and acceptance criterion. For each alignment, the earthwork cost was minimized using linear programming. This study is a sequel to this earlier study. It employs various heuristic techniques for optimizing vertical alignment of a forest road section and compares their performances in a simple application. The results indicated that heuristic techniques may be useful tools for identifying the optimum vertical alignment at acceptable computational time.