The following speed limits are established in Section 321.285 of the Code of Iowa and any speed in excess thereof is unlawful unless specifically designated otherwise in this chapter as a special speed zone.
1. Business District - twenty (20) miles per hour.
2. Residence or School District - twenty-five (25) miles per hour.
3. Suburban District - forty-five (45) miles per hour.
Violations of this section shall be cited under Section 62.01(85) through 62.01(99), as is appropriate under the circumstances.