Transportation corridor and sub area planning activities are distinguished from area wide planning and project development in that the primary goals are to refine understanding of a specific transportation project and to establish the process by which it can be approved and delivered. This includes developing the information needed to establish the project purpose and need, the range of alternatives to be evaluated and the issues that will define the project’s environmental evaluation and approval framework. The focus in corridor and sub area planning is on project understanding and definition of project objectives and alternatives. Measures at this stage are based on project-specific values and objectives. CSS integration provides a process to define and evaluate the best alternative given the project specific context.