For the seventh straight year the Rockford Police Department ranks first in the state in DUI arrests. That's according to an annual study by The Alliance Against Intoxicated Motorists, which excludes Chicago from the list due to its size.

Mario Villafuerte, Getty Images

Rockford officers compiled 556 arrests in 2013. Officials credit much of their success to three Traffic Investigators assigned as a DUI Task Force that works in the overnight hours. The main purpose of the Task Force is to locate intoxicated drivers in an effort to keep the streets of Rockford safe.

In 2013, Naperville was a close second with 553 arrests, followed by Decatur (485),
Springfield (410), and Carol Stream (392).

The highest DUI arrest rate in the state among departments making at least 200 arrests
was Carol Stream which had 6.43 arrests per sworn officer. The second highest rate of 6.30 was in Loves Park.

The sheriff’s department reporting the most DUI arrests was Lake County (348), while
Cook (306), Winnebago (295), Will (262) and DuPage (245) Counties round out the top five sheriff departments.