As we wrap up 2025, I’m happy to report that the Local Road Research Board (LRRB) had another productive year serving local road practitioners by sponsoring research and educational initiatives focused on the needs identified by local agencies.

With more than 75 active research projects, LRRB addresses all aspects of local transportation systems from maintenance to materials and construction, bridges and traffic safety, to environmental, multimodal, and policy and planning.

The LRRB is led by practitioners, and that’s the secret to our success. The professionals who are responsible for county highways and city streets best understand the problems and challenges. Our research ideas come from local practitioners, and they help guide our projects by participating on Technical Advisory Panels (TAPs).

We are also committed to putting research into practice. Through our Research Implementation Committee (RIC), we sponsor projects that turn research results into real-world applications.

I want to give a shoutout to the county and city professionals who volunteer to serve on TAPs. Whether you are one of the 233 local agency practitioners currently serving or you’ve served in the past, your contribution is essential to delivering outcomes valuable to local agencies.

If you’re interested in sharing your expertise on a TAP, please contact Dave Glyer.  If you have a research idea, let us know by submitting to IdeaScale!

I hope you have a happy holiday season and look forward to working with you in 2026.

Local agency professionals often need to explain to newly elected officials, administrators, and the public what they do, the programs managed and how long it takes to deliver a successful project. This toolbox includes resources that can be tailored for your agency’s use.  It includes Frequently Asked Questions, a PowerPoint presentation template, and a modifiable infographic on ‘How a Road is Built’ along with a maintenance schedule for the life of a road. It also includes Olmsted County’s Public Works Dollar, a tool which can be modified to represent your critical investments needed to maintain a safe and effective transportation system.

Local agencies in Minnesota have traditionally used precast box culverts, though cast-in-place (CIP) culverts were common before precast became standard. During the COVID-19 pandemic, rising costs, delivery delays, and fewer suppliers led agencies to reconsider CIP options. This project explores which neighboring states use CIP box culverts design standards, develops guidance on when to use precast versus CIP box culverts, and synthesizes local pilot projects using CIP. It also includes guidance on using the Missouri Department of Transportation (MoDOT) CIP design process; a research process acceptable to MnDOT.

As the transportation network continues to evolve, change, and adapt, local agencies are looking for best practices regarding residential roadway design. In this project, researchers reviewed Minnesota State Aid design standards and compared them to other design standards being used nationally to develop a suggested best practice for residential roadway widths. It also compares these standards with those used in neighboring states and across the country to propose a best practice for determining roadway width on urban residential roads.

School bus stop-arm violations are a common occurrence nationwide. In Minnesota, data analysis indicates significant underreporting of these violations due to lengthy and inconsistent reporting and enforcement processes. This project examined current processes and recommended improvements to encourage higher rates of reporting and enforcement. Guidance includes developing consistent reporting standards and creating a statewide web-based centralized reporting portal to streamline state reporting and enforcement processes and aggregate violation data.

Availability of good quality aggregate materials for local roads and highways is often insufficient to meet increasing demand. However, supplies of plastic waste are plentiful. Incorporating recycled plastic into aggregate for transportation infrastructure is of growing interest. In this study, researchers tested plastic waste material in both asphalt and concrete pavement mixtures. While further testing is needed, plastic modified pavement mixes showed potential for equal or improved performance and environmental, economic and sustainability benefits.

Effective stormwater management helps keep roadway contaminants from entering Minnesota waters. Management practices include soil and vegetation in roadside bioretention systems that filter heavy metals and hydrocarbons. Based on other studies, retention and transformation of roadside pollutants should be improved by biochar application to existing or engineered soils. Abundant sources of biomass can be used to produce biochar, a soil amendment with numerous benefits. Researchers identified biochar specifications for effective use in stormwater treatment to support the next phase of testing and development of biochar design guidance.

We are seeking information on lightweight fill (LWF) use in Minnesota for the LRRB research project, Design Guidance and Best Practices for the Use of Light Fill.

LWF materials are engineered or recycled materials with desirable properties suitable for embankment and pavement structure applications, such as reducing cost and addressing the geotechnical challenges of soft compressible subgrade in road construction.

Knowledge gaps remain in understanding their durability and long-term performance, environmental impacts, and specific construction techniques. This project will assist in bridging those gaps. Your responses will help us develop practical recommendations and inform future design guidelines. Survey deadline: Dec. 31.

• Nicollet County: Minnesota SMART Transformation Award for the Portable Ground-Force Sign Puller, which pulls signposts in difficult areas and can be safely operated by one person. 

For details about the Build a Better Mousetrap competition and this year's projects, visit Build a Better Mousetrap Winners. The Minnesota competition is sponsored by the Minnesota Local Road Research Board and administered by Minnesota LTAP.