The main purpose is to identify the possibility of calculating ecological impact as an opportunity cost to estimate total costs of each alternative and to test the feasibility of the high-speed rail routes designed with different variables. If ecological impact can be accounted for as economic costs are, would it be safe to say a route with the shortest physical (Euclidian) distance is the most economically viable option? If the difference in construction and operation costs, the two most commonly used cost elements in conventional feasibility studies, is compensated by ecological benefits, is it reasonable choose a route that is environmentally beneficial, albeit slightly more circuitous than the shortest route? These are the main questions of this study, and the author answers using the spatial decision support system and ecosystem valuation approaches. The results imply that the saved ecological benefits may compensate for the induced losses in the long run, and thus, choosing a route with more ecological benefits could become a viable solution.