The Street Superintendent shall cause to be placed and maintained traffic control devices when and as required under this Traffic Code or under State law as traffic conditions may require to regulate, guide, or warn traffic. The Street Superintendent is also authorized and responsible for placing and maintaining traffic control devices for emergency or temporary traffic control devices for the duration of an emergency or temporary condition as traffic conditions may require to regulate, guide, or warn traffic. The Street Superintendent shall keep a record of all such traffic control devices.
(Code of Iowa, Sec. 321.255)