Idaho Code § 61-322
No common carrier subject to the provisions of this act shall charge or receive any greater compensation in the aggregate for the transportation of persons or of a like kind of property for a shorter than for a longer distance over the same route or line in the same direction, within this state, the shorter being included within the longer distance, or charge any greater compensation as through rate than the aggregate to [of] the intermediate rates; but this shall not be construed as authorizing any such common carrier to charge or receive a greater compensation for a shorter than for a longer distance or haul over the same line or route in the same direction. Upon application to the commission such common carrier may, in special cases, after investigation, be authorized by the commission to charge less for a longer than for a shorter distance for the transportation of persons or property, and the commission may from time to time prescribe the extent to which such carrier may be relieved from the operation and requirements of this section.
Idaho Code § 61-322