Iowa Code § 327D.13: Rates.

1. a. A common carrier subject to this chapter shall not charge more for the transportation of persons or property than a fair and just rate or charge.

b. A common carrier shall not:

(1) Charge more for the transportation of persons or property for a shorter distance than for a longer distance in the same direction on the same route.

(2) Charge more for a through rate than the aggregate of the intermediate rates.

2. However, upon application by a common carrier, the department may in special cases and after investigation prescribe the extent to which the carrier is relieved from compliance with this section.