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Agency Alert

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Reconstruction of Intersection of Illinois 40 and Science Ridge Road

The Illinois Department of Transportation has undertaken a pre-Phase I (Preliminary Engineering and Environmental) Study of the intersection of Illinois 40 and Science Ridge Road north of the city of Sterling. This study will examine suitable traffic control alternatives that address the safety and mobility of traffic currently experienced at the intersection.

Currently, this intersection is a two-way stop intersection with flashing beacon lights located on each leg of Science Ridge Road. The land surrounding the intersection is open farmland with residential subdivisions, hospital, and many large and small commercial businesses lying within the vicinity.

During the pre-Phase I Study process there will be opportunities for stakeholder input and feedback. Phase I, Phase II (prepare contract bid plans), and Phase III (construction) are currently unfunded.

Virtual Public Meeting:
Date: Wednesday, April 28, 2021
Time: 6 to 7 p.m.
Watch now

Overview and Scope

Proposed for this intersection is a conversion into a modern roundabout with a 14-foot-wide circulating single lane. The center of the roundabout and long splitter islands will deflect entering vehicles approaching the roundabout.

A 14-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. Lighting around the roundabout would be installed.

Existing Conditions

Get Involved

As the Illinois 40 and Science Ridge Road intersection project study progresses, IDOT will periodically update this website to assure that the motorists of Illinois are kept informed of project developments, public involvement opportunities, and construction related activities.

Public Meetings

A virtual public meeting will be held on Wednesday, April 28, from 6 to 7 p.m. to introduce the proposed plan. The meeting will be recorded, and the exhibits and presentation will be posted here for review. Please visit here for updates.

Comments can be sent to:
Region Two Engineer
Attn: Studies and Plans
Illinois Department of Transportation
819 Depot Avenue
Dixon, Illinois 61021-3500

Or by email to:

Brad Cushman, Project Manager and Designer

Or submit a comment/question form:
Submit Question/Comments (


Illinois 40 and Science Ridge Road Renderings

Roundabout Information

Driving Simulations

Intersection Alternatives