Least-cost design of highway geometry

In spite of being in existence for decades, the present practice of two-lane horizontal curve design has several drawbacks. In consideration of the drawbacks of the present design practice and based on expected total cost and expected change in total costs, models are developed for determining optimum degree of curvature for a given section of new or existing highway. A model is developed to accommodate the consistency and environmental constrains that are critical in road construction in difficult terrain.