Approximately 50% of roads in Minnesota are gravel. The performance and long-term sustainability of such roads depend on the quality of the surface layer. Unbound large particles can form an unstable road surface that becomes rough, developing potholes and corrugations as this material is scattered by vehicles or washed away by rain. As a result, more frequent maintenance and reconstruction is required, which becomes very expensive for Minnesota counties.
Continue reading New Project: Evaluation of Gravel Stabilizer Used on Gravel Roads and ShouldersAll posts by Julie Swiler
MnDOT Library is Among State Government Libraries Recognized by Gov. Walz
Gov. Tim Walz proclaimed April 23-29 Capitol Area Library Consortium Week to recognize CALCO libraries during National Library Week.
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MnDOT Library launches digital library
The MnDOT Library recently got a request for a copy of Minnesota Standard Specifications for Highway Construction from 1938. It might seem obscure, but the request was easy to fulfill because a digitized version of the manual was readily available in the newly launched MnDOT Digital Library.
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New Project: Update of Stormwater Management Best Practices Manual
The Local Road Research Board published the Stormwater Best Management Practice (BMP) Maintenance Resource Guide in 2009, and best practices for stormwater management have since evolved. Much has been learned about the benefits and limitations and inspection and maintenance activities of stormwater ponds, bioretention facilities, underground treatment devices, underground detention, and infiltration. Regulatory requirements have also changed as indicated in the Minnesota Stormwater Manual.
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New Project: Red Light Running Warning System
Red-light violations at traffic signals are a major contributor to crashes and fatalities. Right-angle type crashes typically account for the most serious of these collisions, and most of them are caused by vehicles running red lights. This research will explore technology that could be used to warn drivers when they are about to run a red light.
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New Project: Sustainable Application of Tire Derived Aggregate in Stormwater Infiltration/Treatment
The reuse of old tires that often end up in landfills has a significant environmental benefit. Tire derived aggregate (TDA), a waste product from automobile tires, can be used in stormwater treatment systems and has shown to be effective at retaining phosphate. However, TDA does not prevent the leaching of metals including zinc and copper.
Developing media for stormwater infiltration/filtration that uses TDA in combination with materials that can capture metals has several advantages. It would prevent more pollutants from being released into Minnesota’s lakes and streams, save on landfill space and reduce stormwater management costs.
“The use of TDA has been proposed in the past for use in stormwater treatment. However, local agencies aren’t very familiar with the product being used for this application and have concerns about its potential to contaminate groundwater resources,” said Mark Hansen, city engineer, City of Coon Rapids. “Initial research is showing positive benefits for the use of TDA as a component of the stormwater treatment process, while minimizing its impacts to groundwater. Using TDA for this application provides a great opportunity to redirect old car tires from landfills and beneficially reuse them to assist in providing stormwater treatment.”
Objectives
- Select blend materials identified in literature review and mix them in different ratios with TDA.
- Measure the pollutant removal performance from runoff, leaching of zinc and copper from TDA, and infiltration capacity of each mix.
- Analyze the observed values to choose the suitable blend material/ratio.
- Perform lab batch tests to evaluate the potential leaching or removal of polyfluoroalkyl substances (PFAs) by TDA and the blends.
- Determine impact of biofilms on the leaching of zinc and copper from the mix (Biofilms will be grown on an already defined mix of TDA with blend material).
- Conduct outreach on project results and implications to management to key stakeholder groups.
Project Details
- Estimated Start Date: 06/03/2022
- Estimated Completion Date: 06/30/2025
- Funding: Local Road Research Board
- Principal Investigator: John Gulliver
- Co-Principal Investigator: Meijun Cai
- Technical Liaison: Mark Hansen
Details of the research study work plan and timeline are subject to change.
To receive email updates about this project, visit the Local Road Research Board website to subscribe.
Roadside Safe Spaces for Butterflies and Bees
Pollinators such as rusty-patched bumble bees and monarch butterflies, critical to our eco-system, are at risk due to the loss of native habitat. A University of Minnesota research team, with support of MnDOT and the Local Road Research Board, studied whether restored roadsides could provide safe habitats for declining pollinator populations.
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Crossroads 