The Illinois Department of Transportation (IDOT) welcomes you to the official website for the IL Route 159 Study in Madison and St. Clair Counties in Illinois. This website contains project information, a location map, and general information regarding upcoming public involvement efforts relating to the effort to improve IL Route 159 through Collinsville, Illinois.
We encourage your participation and feedback in this study. Please feel free to contact us at the address shown by clicking on “Contact Us” at the top of the page.
Also, if you would like to receive mailings regarding the study, please email us at
The proposed project will extend from South Morrison Avenue north through Collinsville to Belt Line Road. A detailed description of the improvements will be developed through the public involvement process. The Illinois Department of Transportation (IDOT) has set specific goals to improve the capacity of IL Route 159 utilizing two-2 through lanes in each direction and reduce the accident rates at high accident locations within the project limits.