Market Place Intersection & Roundabout

The Lincoln Trail Business District is the busiest retail center in St. Clair County, Illinois. The intersection of Market Place and IL-159 serves as the entrance to the Lincoln Place and the St. Clair Square shopping centers.  On Market Place, a 600-foot long road segment between the DSW / Petco entrance previously had three, closely-spaced, full access intersections that operated poorly due to high traffic combined with driver frustration.  Specifically, the intersection of Plaza Drive and Market Place had the highest crash rate in St. Clair County largely due to uncontrolled turning movements.  To address these safety concerns, the City converted the intersection of Plaza Drive and Market Place from a full access, two-way stop controlled intersection to an intersection style that restricts left-turn movements.  To help reduce vehicle staking through the Plaza Drive intersection, an eastbound dedicated thru lane was added at the intersection of Market Place and IL-159.

Oates Associates worked with the City to prepare a successful Congestion Mitigation Air Quality (CMAQ) grant application and to coordinate design elements with affected commercial business stakeholders, the Federal Highway Administration, and the Department of Transportation. Manual traffic counts were conducted and SYNCHRO/HCS traffic models were created using the traffic counts and other input data.

Phase II of this project involves the construction of a roundabout at the intersection of Commerce Lane and Market Place. The current intersection is a four way stop control with heavy vehicle delay in two of the legs. Oates determined that a roundabout would reduce the vehicle delay for these two legs by 50%. Oates worked with the City to secure another CMAQ grant for this phase. This phase of the project will also add pedestrian improvements and bring the intersection into ADA compliance.