Across Minnesota, many local road agencies can’t afford to maintain their distressed low-volume roads. Converting such roads to unpaved (gravel) roads, an approach used nationwide, can reduce costs and improve road quality, but information about the practice has not been widely available.
To meet this need, the Minnesota Local Road Research Board (LRRB) developed a comprehensive information source on effective practices for converting severely distressed paved roads to acceptable engineered unpaved surfaces. The guide, targeted to Minnesota’s specific needs, includes tools for decision making and communicating with the public. The project was recently named the LRRB's High Value Project of the year and won a 2020 AASHTO Sweet Sixteen Award. (The Sweet Sixteen are high-value projects selected by the four regions of AASHTO’s Research Advisory Committee.)
The guide is based on a 2015 National Cooperative Highway Research Program (NCHRP) synthesis report: Converting Paved Roads to Unpaved. The synthesis identified states and agencies that have conducted road conversions; the relevant tools, metrics, and procedures involved in the process; and related concerns and needs.
For the LRRB guide, a research team selected and transformed the extensive information presented in the 2015 study into a shorter scope and more visual format that would be comprehensive, succinct, and accessible. The guide includes:
- Methods to determine if a road is a candidate for conversion, including how to determine an existing road’s materials and condition.
- Methods to convert a road from paved to unpaved, including design, construction, maintenance, performance-based materials specification, chemical stabilization, and dust control.
- Life-cycle cost analysis tools that compare the life-cycle costs of unpaving versus maintaining the road in its current condition or rehabilitating the road to its original condition.
- Tools to inform and communicate with the public effectively, since most people who will be affected by a road conversion project will not immediately expect or want a gravel road as a maintenance solution. Early and effective communication is essential for road user understanding and acceptance of the process.
- Safety implications of unpaving.
“Many local engineers have reached the same low point in considering their severely distressed low-volume roads,” says Tim Stahl, county engineer for Jackson County. “They can now find in this guide a consistent and innovative approach for distressed road management in Minnesota and surrounding states.”
The LRRB project page has the final guide and video—both titled Converting Severely Distressed Low-Volume Paved Roads to Engineered Unpaved Roads—as well as a webinar and other materials.
Learn more:
- Converting Paved Roads to Unpaved
- AASHTO Sweet Sixteen Award
Guide to Converting Distressed Low-Volume Paved Roads to Unpaved Roads
Across Minnesota, many local road agencies can’t afford to maintain their distressed low-volume roads. Converting such roads to unpaved (gravel) roads, an approach used nationwide, can reduce costs and improve road quality, but information about the practice has not been widely available.
To meet this need, the Minnesota Local Road Research Board (LRRB) developed a comprehensive information source on effective practices for converting severely distressed paved roads to acceptable engineered unpaved surfaces. The guide, targeted to Minnesota’s specific needs, includes tools for decision making and communicating with the public. The project was recently named the LRRB's High Value Project of the year and won a 2020 AASHTO Sweet Sixteen Award. (The Sweet Sixteen are high-value projects selected by the four regions of AASHTO’s Research Advisory Committee.)
The guide is based on a 2015 National Cooperative Highway Research Program (NCHRP) synthesis report: Converting Paved Roads to Unpaved. The synthesis identified states and agencies that have conducted road conversions; the relevant tools, metrics, and procedures involved in the process; and related concerns and needs.
For the LRRB guide, a research team selected and transformed the extensive information presented in the 2015 study into a shorter scope and more visual format that would be comprehensive, succinct, and accessible. The guide includes:
- Methods to determine if a road is a candidate for conversion, including how to determine an existing road’s materials and condition.
- Methods to convert a road from paved to unpaved, including design, construction, maintenance, performance-based materials specification, chemical stabilization, and dust control.
- Life-cycle cost analysis tools that compare the life-cycle costs of unpaving versus maintaining the road in its current condition or rehabilitating the road to its original condition.
- Tools to inform and communicate with the public effectively, since most people who will be affected by a road conversion project will not immediately expect or want a gravel road as a maintenance solution. Early and effective communication is essential for road user understanding and acceptance of the process.
- Safety implications of unpaving.
“Many local engineers have reached the same low point in considering their severely distressed low-volume roads,” says Tim Stahl, county engineer for Jackson County. “They can now find in this guide a consistent and innovative approach for distressed road management in Minnesota and surrounding states.”
The LRRB project page has the final guide and video—both titled Converting Severely Distressed Low-Volume Paved Roads to Engineered Unpaved Roads—as well as a webinar and other materials.
Learn more:
- Converting Paved Roads to Unpaved
- AASHTO Sweet Sixteen Award
- Guide to Converting Distressed Low-Volume Paved Roads to Unpaved Roads