Best Practices for Improving Subgrade DrainageStatus: CompleteReport Date: 06/12/2023 Summary: Poor drainage may reduce the life of a roadway by 50%, but subsurface drainage systems can be costly. Considerable research exists on the design and construction of roadway drainage systems. Counties throughout Minnesota have experience with the design, construction and maintenance of these systems. However, there was a need to synthesize the available research and firsthand experience into a practical manual. This project identified the successes and lessons learned to create a best practices guide that will improve how subsurface drainage is implemented. The focus was not solely on new construction but also on how to update and maintain existing roads, particularly frost-susceptible gravel roads. Final Deliverables: Guidebook #2023RIC01 Research Summary Related Materials: Developing a Best Practices Manual for Roadway Drainage - (Blog Post) Related Research: