Des Peres Road Roundabout

Project Summary

In 2017, the City of Des Peres utilized a MoDOT TEAP grant (Traffic Engineering Assistance Program) to study traffic on Des Peres Road. One of the recommendations of the study was reconfiguration of the intersection of Des Peres Road with Old Des Peres Road. This intersection was the site of frequent accidents due to its unique nature. While many laypeople suggested a four-way stop, the volume during peak periods would cause significant delays and backups. The study suggested either a traffic signal or roundabout. Given the geometry and setting of the location, a roundabout was deemed the better option.

The City applied for a CMAQ grant (Congestion Mitigation & Air Quality) in May 2018 through the East-West Gateway Council of Governments, but was unsuccessful. Over the 2018-2019 winter, the City designed and implemented minor modifications to the intersection to reduce accidents. We are happy to report that rear-end collisions have been reduced by this modification. However, right-angle collisions persist. The City again applied for a CMAQ grant in 2019, and the the grant was approved, providing 80% reimbursement for all phases of the project: Design 2020, ROW 2021, Construction 2022. The total project budget was approximately $1.6M.

Due to the size of the project, MoDOT’s Qualification-Based Selection process must be strictly followed in choosing an engineer for design. A Request for Qualifications (RFQ) was posted with MoDOT in November 2019, with responses due 12/11/19. Letters of interest were received from eight (8) consultants, then reviewed in order to select the best-qualified firm, in accordance with state and federal law. Three finalists were interviewed in January 2020 by staff in order to further evaluate their qualifications. CMT was selected, and their contract was approved by the Board of Aldermen 3/23/20. 

We received authority to advertise from MoDOT and FHWA on 4/29/22 and began advertisement the same day in order meet their 4-week requirement. Bids (2) were opened 5/27 and came in significantly higher than our funding and estimate. We attribute this partly to the timing of the bids, since most contractors already had full schedules for the years. As a result, the Board of Aldermen voted 6/13/22 to reject all bids and rebid the project this for 2023 construction.

Handouts and Exhibits: Project Information Sheet 

Roadway Plan (click to download full-sized PDF)

Landscaping Plan (click to download full-sized PDF)

Project Update and Schedule

The project was readvertised in early October, with bids due 11/10. Unfortunately, bids came in slightly higher than before, a construction cost of approximately $2.2M. The funding program caps the federal funding at 80% of the estimated costs at the time of application (2019). Given the extreme increase in construction costs over the past two years, this would have resulted in the City paying more than 50% of the project's cost. As a result, the Board of Aldermen voted on 12/12/22 to return the current funding, and reapply in the next round of funding. In February 2023, we applied for a new CMAQ grant, and in May our project was selected for funding by the East-West Gateway Council of Governments. While it will take some time to get all of the agreements in place, we anticipate construction will take place in 2024. With this round of funding, we estimated the total construction cost (including testing & inspection) at $2.7M, with 80% federal reimbursement ($2.2M). 

Updated 5/10/23