; (J) that interregional planning should be done regularly and not less frequently than once every 3 years; and (K) the elimination of arbitrary project voltage, size, or cost requirements for interregional solutions; and (3) cost allocation methodologies that reflect the multiple benefits provided by interregional solutions. (b) Timing Not later than 18 months after the date of enactment of this Act, the Federal Energy Regulatory Commission shall promulgate a final rule to complete the rulemaking initiated under subsection (a).