The Kittson County Highway Department developed a low-cost way to strengthen dirt roads—or at least make them more accessible—by adding sandy aggregate (Class 3) with the dirt. An area railroad provided excess piles of this sandy aggregate for the project.
The project, funded by a $15,000 grant from the Minnesota Local Road Research Board’s OPERA Program, began in mid-June and ran through mid-August 2019. A test-rolling in July showed an improvement of 1 inch less rutting (a 38 percent decrease) over the first mile and an improvement of nearly an inch less rutting (a 30 percent decrease) for the second mile. A second test-rolling in August showed a 42 percent decrease in rutting along the first mile and a 41 percent decrease for the second mile.
Local farmers in the research project area had expressed skepticism about the project. But, after the sandy aggregate consolidated with the dirt over time, the farmers felt that the road did perform better for the heavy wheat harvest loads in August.
The Kittson County project team feels that the findings will benefit other local agencies, townships, and even private landowners with access to low-cost material and a goal to improve local dirt roads.
Learn more:
- Fact sheet: Sand-Stabilized Dirt Roads (LRRB, Aug. 2020, PDF)
- Watch the video demonstration (LRRB, Aug. 2020, 2:57)
- Local Operational Research Assistance (OPERA) Program