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Boone Co - Illinois 173 and Caledonia Road Intersection Study
The Illinois Department of Transportation is currently conducting a preliminary engineering and environmental study (Phase I) for the intersection reconstruction of Illinois 173 at Caledonia Road in Caledonia in Boone County.
This intersection, constructed in 1928 and reconstructed in 1993, provides access to Caledonia from the west on Illinois 173. The purpose of the study is to reconstruct the deficient intersection into a modern four-leg roundabout. The project also includes the reconstruction of the drainage ditches, culverts, and other safety improvements as needed.
During the Phase I Study process there will be opportunities for stakeholder input and feedback. Contract letting is tentatively set for FY 2029.
Public Meeting:
Date: Wednesday, Oct. 29, 2025
Time: 2 to 6 p.m.
Location: Caledonia Congregational Church, 14730 Oak St., Caledonia, IL 61011
Proposed for this intersection is a conversion from a four-leg, two-way stop controlled intersection into a modern four-leg roundabout with a 20-foot-wide circulating single lane. The center of the roundabout and long splitter islands will deflect entering vehicles approaching the roundabout. A 10-foot-wide concrete truck apron, located just outside of the central island, is proposed. This area will accommodate large trucks, farm equipment and emergency vehicles, providing them with an additional area to maneuver through the circle. Entering vehicles would yield to traffic circulating counterclockwise in the circle.
This project was initiated as an intersection design study due to high frequency of crashes and a recent fatality. Approximately 80% of crashes in the past 5 years are related to turning movements. Our goal for the proposed roundabout is increase safety by reducing turning conflict points and calm traffic with minimal disruption of flow.
- Display Boards - 10-29-2025 Meeting
- Photo Exhibits
- Roundabout Rendering (YouTube)
- Roundabout Exhibit
- Typical Sections
A public meeting will be held on Wed., Oct. 29 from 2 to 6 p.m. at the Caledonia Congregational Church, 14730 Oak St., Caledonia. All exhibits shown here will also be shown at the public meeting.
Comments can be sent to:
Corey Conderman
Studies & Plans Team Leader
Illinois Department of Transportation, District 2
819 Depot Avenue
Dixon, IL 61021
Email: Corey.Conderman@illinois.gov
Learn more about IDOT projects. For IDOT District 2 updates, follow us on Twitter at @IDOTDistrict2 or view area construction details on IDOT's traveler information page on GettingAroundIllinois.com.