Geographic Information System–Based Analysis of Right-of-Way Cost for Highway Optimization

At the planning stages of a highway project, various location alternatives must be explored, subject to a set of design constraints. A computerized tool with which to compare alignment alternatives would significantly reduce the time and resources spent as well as help find a minimum cost (or maximum net benefit) solution. Highway design optimization (HDO) is a computerized process that minimizes an objective function composed of significant highway costs, subject to a set of design constraints, including curvature, gradient, and sight distance. Several costs of alignments, such as right-of-way, earthwork, and environment costs, are sensitive to geography. A geographic information system (GIS) may be exploited to compute such costs for use in HDO models (HDOMs). Most known HDOMs focus only on refining the optimization approach and do not provide a comprehensive formulation for all costs sensitive to alignment. Provided is a comprehensive formulation for right-of-way cost computation. A GIS-based algorithm is developed to compute the right-of-way cost, which is integrated with an HDOM based on genetic algorithms. Two examples are used to demonstrate the effectiveness of the proposed approach.