18 CFR § 342.4 - Other rate changing methodologies.
(a) Cost-of-service rates. A carrier may change a rate pursuant to this section if it shows that there is a substantial divergence between the actual costs experienced by the carrier and the rate resulting from application of the index such that the rate at the ceiling level would preclude the carrier from being able to charge a just and reasonable rate within the meaning of the Interstate Commerce Act. A carrier must substantiate the costs incurred by filing the data required by part 346 of this chapter. A carrier that makes such a showing may change the rate in question, based upon the cost of providing the service covered by the rate, without regard to the applicable ceiling level under § 342.3.
(b) Market-based rates. A carrier may attempt to show that it lacks significant market power in the market in which it proposes to charge market-based rates. Until the carrier establishes that it lacks market power, these rates will be subject to the applicable ceiling level under § 342.3.
(c) Settlement rates. A carrier may change a rate without regard to the ceiling level under § 342.3 if the proposed change has been agreed to, in writing, by each person who, on the day of the filing of the proposed rate change, is using the service covered by the rate. A filing pursuant to this section must contain a verified statement by the carrier that the proposed rate change has been agreed to by all current shippers.