This work addresses the capital cost implications of environmental impact allied to new highways. Those environmental impact considerations which are capable of being evaluated in terms of capital cost are distinguished from those which are concealed and cannot be evaluated using monetary values. The new design technique the Commercial Route Methodology (CRM) has been developed to evaluate in capital cost terms the concealed and unquantifiable impacts inter alia, visual intrusion, visual obstruction, effects on agriculture, ecological concern, heritage and conservation areas and aesthetic aspects.