321.492A  Quotas on citations prohibited.
  A political subdivision or agency of the state shall not order, mandate, require, or in any other manner, directly or indirectly, suggest to a peace officer employed by the political subdivision or agency that the peace officer shall issue a certain number of traffic citations, police citations, memorandums of traffic violations, or memorandums of faulty equipment on a daily, weekly, monthly, quarterly, or yearly basis.
85 Acts, ch 226, §1; 96 Acts, ch 1034, §25