The Board shall periodically review its cost accounting rules and shall make such changes in those rules as are required to achieve the regulatory purposes of this part. The Board shall insure that the rules promulgated under this section are the most efficient and least burdensome means by which the required information may be developed for regulatory purposes. To the maximum extent practicable, the Board shall conform such rules to generally accepted accounting principles.

As required by the rules of the Board governing discovery in Board proceedings, rail carriers shall make relevant cost data available to shippers, States, ports, communities, and other interested parties that are a party to a Board proceeding in which such data are required.

To obtain expense and revenue information for regulatory purposes, the Board may promulgate reasonable rules for rail carriers providing transportation subject to the jurisdiction of the Board under this part, prescribing expense and revenue accounting and reporting requirements consistent with generally accepted accounting principles uniformly applied to such carriers. Such requirements shall be cost effective and compatible with and not duplicative of the managerial and responsibility accounting requirements of those carriers.