The methodology shall consider direct and indirect costs and benefits for all reasonable options to meet planning goals and objectives. The methodology shall treat demand and supply resources on a consistent and integrated basis. The regional transportation planning organizations shall consult the guidelines set forth by the department for implementing a least-cost planning methodology. Regional transportation plans should incrementally incorporate least-cost planning methodologies as these concepts are developed. The regional transportation plan adopted after July 1, 2000, shall be based on a least-cost planning methodology appropriate to the region.