TH 52/CSAH 24 Interchange Preliminary Design and Environmental Assessment

Cannon Falls, Minnesota

The TH 52 corridor has undergone many changes to eliminate at-grade intersections and remove problematic safety concerns. The two existing traffic signals in Cannon Falls were the last remaining traffic signals on the corridor between the Metro area and the City of Rochester, one of which represented one of the worst accident rates in the State of Minnesota. MNDOT District 6 retained SRF to develop an interchange location and design to replace these remaining traffic signals along TH 52 in Cannon Falls.

In order for the new interchange to operate properly and to meet the goals of the Interregional Corridor System, other direct access points and median crossovers also needed to be removed – these changes necessitated developing frontage roads and promoting local connections to the new interchange.

Due to the extent of the changes, SRF conducted an extensive review of the interchange location options and thoroughly reviewed the pros and cons of each location option. Discussions were held with the local agencies, including the area townships, local stakeholders, businesses, and regional interests in order to understand underlying local issues as well as to explain the opportunities each interchange option presented to the communities affected. The result of the early reviews and discussion was an Interchange Location Report that detailed the process and how decisions were made so that the agencies would have a document for future reference.

Once the location was accepted by the affected agencies, SRF lead the development of the design alternatives. This involved detailed studies of interchange configurations, local road connectivity, and intersection control methods, including roundabouts. Through an iterative process with the Project Steering Committee a preferred alternative was honed in upon, and ultimately selected with consensus provided by all the agencies involved. As the preferred alternative was developed into a MnDOT Level I Staff approved layout, the Environmental Assessment was also developed in order to progress the project towards getting the required environmental approvals. The final component of this project was to complete and record an official map of the project improvements in order to preserve the R.W. for these future improvements.