Iowa Code § 314.11

Telephone, telegraph, electric transmission, and pipelines may be permitted to use any highway bridge on or across a state line on such terms and conditions as the agency or officials jointly constructing, maintaining, or operating such bridge may jointly determine. No discrimination shall be made in the use of such bridge as between such utilities. Joint use of telephone, telegraph, electric transmission, or pipelines may not be required. No grant to any public utility to use such bridge shall in any way interfere with the use of such bridge by the public for highway purposes.