The traffic unit is comprised of two sergeants and twenty deputies.  Their primary function is to reduce the number of traffic crashes in Polk County, especally those resulting in injuries and fatalities.  This is generally accomplished through targeted enforcement of traffic laws and the delivery of community education programs.

Traffic Unit deputies have recieved a great deal of specialized training that provides a foundation for the completion of their assigned duties, which also include the investigation of traffic crashes; from those that are minor in nature to those that involve a fatality.

In addition, a number oif Traffic Unit deputies are assigned full-time to the enforcement of traffic laws related to driving while under the influence (DUI) of alcohol or other drugs, resulting in hundreds of arrests each year.