Research Implementation Committee

This research project summarizes various aspects of pedestrian crossings. The document is focused on pedestrian crossings in a rural environment. This project seeks to provide a comprehensive overview of pedestrian crossings for both pedestrians and drivers by examining Minnesota statutes, summarizing key features of pedestrian crossings, synthesizing findings from existing research reports and studies, and integrating other relevant resources.

This spreadsheet is part of the final deliverable for Report 2024RIC07, " Best Practices for Dust Control in Minnesota."

This appendix is part of the final deliverable for 2024RIC07, "Best Practices for Dust Control in Minnesota," published November 2024.

This appendix is part of the final deliverable for 2023RIC07, " Best Practices for Dust Control in Minnesota," published November 2024.

More than 50 percent of the road network in the United States are gravel roads, underscoring their crucial role in the transportation system. However, one of the drawbacks and biggest complaints of gravel roads is the dust they generate when vehicles pass, causing inconvenience for residents from dust that settles on homes, yards, and parked cars. Dust can also reduce the safety for drivers due to impaired vision. Recently, counties have received calls from residents inquiring about environmental, health and corrosion concerns with dust and dust control suppressants. This document investigates these additional questions as well as reviews and updates previous LRRB reports on dust control.

While seal coating has been widely used as a cost-effective strategy in asphalt pavement preservation by the Minnesota Department of Transportation (MnDOT) and local agencies to extend the life of pavements, some cities and counties in Minnesota have reported their concerns about the premature stripping of street pavements that have been seal coated. The Local Road Research Board (LRRB) completed a study on seal coats titled, Is Seal Coating Counterproductive or Not? to address these issues. The purpose of this document is to provide users with quick access to some of the research and resources available in Minnesota

Boulevards are the open space, located just behind the curb, along a roadway. Boulevards serve the essential functions of providing snow storage space for roads and sidewalks, a place for rain and runoff to soak into the ground, and attractive green space in the neighborhoods of our cities. Street trees, or trees planted in the boulevard along a roadway are valuable environmental infrastructure as they save energy and lower temperatures, reduce greenhouse gases, reduce stormwater runoff, and improve aesthetics. Thoughtful planning ensures that the right tree is planted in the right place and with the right maintenance. However, boulevards are often a challenging location to plant trees because of the limited space, utility conflicts, and salt residue from winter maintenance among other factors. This guide will help evaluate the feasibility of the boulevard to support tree planting and suggest tree species with a higher survivability rate for use in the boulevard. Residents and business owners may be concerned about who is responsible for the care and maintenance of trees planted in the boulevard and the cost. City staff and elected officials who support healthy tree lined neighborhoods seek communication resources to convey the many positive attributes of planting diverse tree species. The following best practices are recommended for the successful tree selection for planting in boulevard locations.

This presentation is one of the deliverables for project 2024RIC05, Pavement Marking Retroreflectivity Inspection Methods Webinar.

Roundabouts have been effective at increasing safety and efficiency of vehicle traffic. Traditional roundabout design typically requires a larger “footprint” than a traditional four-way intersection. Over the past few years, more and more agencies are implementing “mini roundabouts,” a type of roundabout characterized by a small diameter that can include fully traversable islands (central island and splitter islands). Currently, there are over 40 mini-roundabouts in Minnesota. The focus of this document was to help Minnesota agencies learn a little more about mini-roundabouts.

Asphalt concrete pavement surrounding utility structure covers is prone to settlement, cracking, breaking up over time, and potholing, and these distresses are particularly common in wet-freeze climates (e.g., Minnesota). Several factors contribute to their formation, including design requirements, collar material type and cut shape, construction practices, frost heave, and backfill settlement. If not properlymaintained, the distressed pavement can lead to ride quality issues and hazards for vehicles and snowplows. Differences in design details and construction practices can result in different performance; however, differences in pavement performance around utility structure covers are not well documented. The main goal of this Minnesota Local Road Research Board (LRRB) project is to fill this knowledge gap bydocumenting regional agency best practices for adjusting utility covers and patching the surrounding pavement. Information is gathered through a review of existing information, a review of standard details from agencies in and around Minnesota, an agency survey, and follow-up discussions with agencies that are generally satisfied with their practices. No single best practice is identified for design details; however, common themes among agencies include the importance of both inspecting and testing during construction and achieving adequate compaction of all pavement patch layers. This document is developed to assist local transportation agency personnel and engineering consultants in improving design and maintenance of asphalt concrete pavement around utility covers. It highlights successful and unsuccessful regional practices and trends, factors contributing to pavement damage around utility covers, timing of inspections and maintenance, and a framework for evaluating and modifying practice.