IL Route 47 Categorical Exclusion II & Noise Study


Kaskaskia Engineering Group, LLC (KEG), in coordination with SEC Group, Inc./HR Green Company, was contracted by the Illinois Department of Transportation (IDOT) to conduct Phase I/II engineering services for the improvement of Illinois Route 47 in Yorkville, Kendall County, Illinois.  The purpose of this project is to provide a safe and efficient transportation system to serve existing and forecasted traffic demands on IL Route 47 between IL Route 71 and Caton Farm Road in Kendall County, Illinois.  Operational deficiencies, as well as insufficient roadway capacities for existing and future travel demands, have led to limited mobility and access issues for current users.  


Illinois Department of Transportation

SEC Group, Inc./Howard R. Green Company

Project Cost:
$98,000 (study fee)


KEG staff completed the Categorical Exclusion II (CE-II) component of the Project Report and the supporting Noise Technical Report, as well as providing assistance with public involvement during the Phase I Study.  The CE-II included the analysis of air quality, water quality, traffic noise, community impacts, and ecology.  The Project Report, indicating no significant environmental impacts were present within the project area, was submitted to IDOT in January 2014.  


The Noise Technical Report was also submitted to IDOT in January 2014 for final approval. This report evaluated traffic noise impacts for the proposed improvements to IL Route 47. KEG environmental personnel measured noise levels at several sites within the project to validate the use of the currently approved TNM 2.5 model for predicting noise.  Once the model was validated, KEG predicted the existing and projected (2040) noise at a total of 19 locations in the project area.  These locations consisted of 12 individual noise sensitive receptors and seven Common Noise Environments (CNE’s).  

Noise level predictions for the Build Alternative indicated that three CNE’s and five individual receptors will experience noise levels that exceed the Noise Abatement Criteria due to an increase in traffic volumes and the proposed roadway alignment.  A barrier analysis was then conducted for each of the impacted receptors.  The results of the analysis suggested noise abatement measures are not likely to be implemented based on preliminary designs.  A final decision on the installation of abatement measures will be made upon completion of the project’s final design and public involvement process. 




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