CSAH 32 Reconstruction, Dakota County, Minnesota
This complex reconstruction project converted a vehicle-centric, two-lane undivided corridor to a two-lane divided typical
The grade raise was complicated as the project is located within the Minnesota River floodplain and the existing roads were constructed on poor soils due to decades of flooding.
MnDOT, the City of New Ulm, Brown County, and Nicollet County developed a vision for transportation improvements on TH 14/15 between Broadway Street and the TH 14/15 intersection. The vision included improvements for safety, increased mobility, and addressing aging infrastructure.
Bolton & Menk led the final design on this $43 million reconstruction and grade raise of 3 miles of TH 14 and 15, including construction of a new interchange at the TH 14/15 intersection, an interchange at Front Street, and three bridges over the Minnesota River and CP Railway. The grade raise was complicated, as the project is located within the Minnesota River floodplain with poor soils. We coordinated with MnDOT’s geotechnical engineers to design a surcharge and wick drain system to stabilize the existing subgrade while expediting the required settlement periods to maintain an achievable construction schedule. Final design included muck excavation, embankment, and wick drains to enable construction of a stable roadbed.
The project included coordination with a multitude of stakeholders, including the City of New Ulm, Nicollet and Brown Counties, MnDNR, and the U.S. Army Corps of Engineers. Final design and bidding document preparation was successfully completed on an accelerated nine-month schedule.
This complex reconstruction project converted a vehicle-centric, two-lane undivided corridor to a two-lane divided typical
The roundabout provides a safer rural intersection to the area.
The primary goal of the study was to increase safety while maintaining corridor mobility.
The roundabout is ideal at a school entrance where signals aren’t needed most times throughout