Arkansas Power & Light Co. (P) petitioned the ICC to institute a rulemaking proceeding for the ICC to create a database of railroad rates (so Ps could comparison shop the rates to their advantage). The ICC (D) denied the petition. Specifically, they sought a determination of the kind of evidence that would be relevant to a Long-Cannon inquiry, the required production of such evidence from railroads nationwide, and the development of standards to be applied in carrying out the statutory requirements. P argued that such a carrier-specific database was a necessary prerequisite to compliance with the policy of the Staggers Act. Ps also asserted that the ICC should halt the railroads' traditional differential pricing practices until the rulemaking was completed. D denied the petition in that Congress had not evinced any intent to require a rulemaking proceeding to implement the Long-Cannon Amendment, in contrast to other sections of the Staggers Act in which Congress has issued such directives regarding implementation; such a study would be inconsistent with the design of the Staggers Act to minimize the need for regulatory control; rules and guidelines for gathering and applying a nationwide database would also be difficult to develop and would be 'enormous and enormously difficult to gather; but making this assessment in individual cases is more productive and efficient than a rulemaking because it will avoid applying a massive reporting burden on carriers which are efficient. Ps sought appealed to compel rulemaking.