Ark. Code Ann. § 23-4-104: Charges, rates, etc., to be just, reasonable, and in compliance with Acts 1919, No. 571, and Acts 1921, No. 124

(a) All charges, tolls, fares, and rates shall be just and reasonable.

(b) No charge shall be made in any tariffs, rates, fares, tolls, schedules, or classifications except as provided in this act.