County Line Road Phase I Study: IL Route 1 to IL Route 50 (Will Co., Illinois)

CLIENT: Will County

Clark Dietz is providing Phase I engineering services for approximately 9.5 miles of County Line Road between IL Route 1 and IL Route 50 along the boundary of unincorporated Will and Kankakee Counties. The study will develop recommended improvements to enhance safety, mobility, drainage, and long-term roadway performance while coordinating with separate IDOT projects at both ends of the corridor.

The photos above show existing roadway and structure conditions along County Line Road before improvements.

The primarily rural corridor includes 20 stop-controlled intersections, an at-grade Union Pacific Railroad crossing, and open-ditch drainage. Four numbered structures carry the roadway over Black Walnut Creek, Rock Creek, Exline Slough, and Trim Creek, with an additional culvert crossing at Marshall Slough. These features require coordinated roadway, drainage, hydraulic, and structural evaluations to guide preliminary design.

Clark Dietz’s services include supplemental field surveys, traffic counts and projections, crash analysis, utility coordination, and geotechnical investigations. Environmental studies, wetland delineation, and special waste assessments will help identify conditions that may influence the recommended improvements. The team will develop preliminary roadway and intersection designs, complete signal warrant analyses, and prepare Intersection Design Studies where needed. Gonzalez Companies will continue its previous work on Structures 046-3232 and 046-3233, maintaining continuity through the required design process.

Public and agency engagement will include stakeholder coordination, public information meetings, a project website, and meetings with Will County, IDOT, the Bureau of Local Roads and Streets, and FHWA. This coordination will support the evaluation of alternatives and development of the recommended improvements.

The study will culminate in a Project Development Report documenting preliminary design, cost estimates, right-of-way requirements, and considerations for final design in accordance with applicable IDOT procedures.