County staff outlines MnDOT-funded rumble-strip pilot for higher-risk segment on County Road

Josh, a county highway official, briefed commissioners that the county secured a Minnesota Department of Transportation pilot HSIP grant to test edge-line and shoulder rumble strips on a high-risk stretch of county roadway. He said the county "received $337,500 for grant money for that project in 2030," and that the construction portion of the pilot would be fully funded by MnDOT while the county provides coordination, inspection and local project management.

Staff explained the site selection follows the county road safety plan and identified segments with higher risk of run-off-road crashes, speed and access density. Commissioners asked specifically why rumble strips are not proposed for a nearby S-curve; Josh said MnDOT recommended excluding that curve because lower posted speeds and homeowner proximity reduce the effectiveness of edge-line rumble strips and could create late-alert hazards on tight curves.

Board members also asked about traffic impacts during installation and whether the work would require detours; highway staff said the operation uses a mobile grooving machine and typically involves minimal, short-duration impacts with standard traffic control. Staff noted one component of the near-term work is related paving (milling and overlay) to improve pavement condition before grooving the rumble strips.

Next steps: the county will execute a grant agreement with MnDOT, finalize mapping of the pilot limits (the packet referenced a segment beginning just east of the City of Isanti), and issue localized notices via the sheriff's office and social media when work is scheduled. The board did not take a formal vote; staff sought and received consensus support to proceed with grant execution and coordination.