Culverts are essential infrastructure for water management that channel water under roads and embankments. Connected concrete pipes may separate and diminish culvert effectiveness by allowing soil and water infiltration. This work examined the most common predictors and likely factors that lead to joint separation in culverts. Investigators concluded that location is the best predictor, and the expansion and contraction of freezing soil are the primary factors causing joint separation. Installing ties on all culvert pipe joints and ensuring backfill material is properly compacted during construction may protect infrastructure and reduce maintenance costs. 

To enhance livability and improve safety for pedestrians at intersections, agencies may install temporary or permanent infrastructure such as curb extensions or pedestrian refuge islands. These installations, especially refuges, are typically considered effective, but more detailed information is needed about their impacts to optimize the benefits. Investigators evaluated the safety outcomes at 12 intersections in Minneapolis and St. Paul before and after the installation of infrastructure. Results offer valuable insights for transportation engineers and planners to consider as they develop and implement strategies to mitigate dangerous conditions for pedestrians.

A successful winter maintenance program necessitates making informed investments in snow and ice management equipment and technologies. These investment decisions involve a complex balance of economic benefits and risks that may not be fully known when agencies allocate their budgets.

This research launched a tool that state agencies can employ to quantify the economic merit of their snow-and-ice programs. Having quantitative data regarding real-world costs will support maintenance program managers in the development of business cases with clear projections for costs and benefits.

Roadside vegetation can cast shade onto the pavement and reduce the melting of snow and ice. It would be reasonable to assume that the need for chemical deicers could feasibly be lessened if roadside vegetation is reduced.

This research project developed a vegetation management guide to offer winter maintenance managers strategies for identifying shade-prone road segments, developing best practices that balance impacts on the environment, prioritizing vegetation removal or pruning, safety, community preferences, and communicating the benefits of roadside vegetation management to the public.

Developing techniques and processes to capture chloride from salt used to treat roads during and after winter storms before it reaches watersheds would provide significant environmental benefits. While extremely challenging, this project attempted to direct chloride-contaminated water to permeable treatment media bags located in roadside ditches to capture chloride. Test results found insufficient chloride capture by the treatment media in this project, but solutions for numerous operational obstacles were identified that will be invaluable to similar projects and testing in the future. 

Thursday, April 16
10:00-11:15 a.m.

Curious about how to improve or inform your project life cycle costing efforts and grow your skills as a steward of public funding? Join MnDOT’s Office of Research & Innovation and the Minnesota Local Road Research Board for this month’s Research Radar: Savings by Design.