Iowa Code Title XV. Judicial Branch and Judicial Procedures [Chs. 595-686] § 668.10. Governmental exemptions

a. The failure to place, erect, or install a stop sign, traffic control device, or other regulatory sign as defined in the uniform manual for traffic control devices adopted pursuant to section 321.252. However, once a regulatory device has been placed, created, or installed, the state or municipality may be assigned a percentage of fault for its failure to maintain the device.

b. The failure to remove natural or unnatural accumulations of snow or ice, or to place sand, salt, or other abrasive material on a highway, road, or street if the state or municipality establishes that it has complied with its policy or level of service for snow and ice removal or placing sand, salt, or other abrasive material on its highways, roads, or streets.