Innovative technology developed by LRRB could potentially reduce the risk of serious crashes at signalized intersections that result from drivers running red lights. Onboard technology that integrates traffic light phasing information with the location and speed of the vehicle can provide reliable warnings and guidance to distracted drivers to prevent them from running red lights.

This project installed a roadside unit at a selected intersection in Scott County, Minnesota, and equipped a car with a GPS chip and software that enabled the vehicle to receive traffic signal phasing information from the unit. Microsimulations of system performance followed by on-road testing demonstrated the system’s ability to issue appropriate warnings based on various traffic signal scenarios.

The design of a channelized right-turn (CRT) can have a significant impact on safety for bicyclists and pedestrians, especially those with sight or other impairments. For example, designing CRTs to have a tighter turn angle will slow vehicles, and installing raised crosswalks will help control speeds or increase the visibility of the crosswalk. This project provides extensive recommendations and best practices for making CRTs safer and more accessible for vulnerable road users, whether the CRT is part of a new construction project or a redesign of an existing facility.

Extensive research and discussions with focus groups thoroughly examined design practices of CRTs in Minnesota and elsewhere, and the resulting benefits and challenges for vulnerable road users. This work led to the development of extensive recommendations and best practices for designing CRTs and mitigating challenges associated with their use. The guidance will be distributed to state and local traffic engineers in Minnesota to promote walkable communities that enhance equity, quality of life and economic efficiency.

Driverless vehicles provide the transportation industry with fiscal and environmental benefits, but concerns remain regarding the interaction between driverless vehicles and drivers of manual vehicles. In Rochester, Minnesota, interactions between a driverless shuttle and other vehicles were observed in a pedestrian-heavy area of the city. Additional research included analyzing driver behavior relative to the shuttle and conducting lab tests to better understand what messaging the shuttle could provide surrounding traffic. The results demonstrated that potential dangers could be mitigated by increasing the speed of the shuttle and displaying clearer messaging on the back of the shuttle to alert drivers to the shuttle’s behavior.

Watch this webinar recording with technical liaison Cory Johnson to learn more.

Asphalt milling is an essential construction activity. It requires concentrated high-intensity applications of force to the existing pavement to remove the asphalt material. The impact that the induced stresses have on the pavement below the mill line is unknown. Consequently, selected milling parameters rarely consider the impact the milling may have on the remaining layers.

This National Road Research study evaluated five milling parameters to understand their impacts on the layer directly below the mill line: the time between milling and post-mill overlay construction, existing pavement structure, temperature while milling, depth of milling relative to layer interface, and rotor speed. The study determined that while milling depth and rotor speed do not significantly impact the properties of the remaining HMA layer, exposure to traffic and weather for two weeks and milling at cooler temperatures can potentially reduce its strength. Further research is needed to evaluate the effects of milling at different pavement temperatures and determine if guidelines for minimum milling temperatures are necessary.

Research Services Academic Research Program – Multi-Award

MnDOT is requesting proposals from colleges and universities for providing academic research on a wide variety of transportation-related topics. Contracts under this program will include research support, implementation and technology transfer and education activities. The intent of this RFP is to establish a list of qualified academic institutions to address specific research issues identified by MnDOT requiring expertise not available within MnDOT. MnDOT will offer contracts for research services to multiple, qualified successful responders. These contracts will provide a mechanism for obtaining transportation research in a convenient and timely manner.

Research Implementation Committee: Implementation of Research Findings (Fiscal Year 2026-2030)

The goal of this program is to deliver to end-users (Minnesota local agencies) the results of applied research conducted by the LRRB, MnDOT, the Federal Highway Administration (FHWA), and local agency generated implementation ideas, through the development and delivery of end-user products most suitable to meet the needs of local agencies. The practical application of emerging methods, processes, procedures, and materials will be accomplished through the development and delivery of end-user products including, but not limited to, resource guides, best practices manuals, executive summaries, interactive computer programs, websites/web applications, webinars, seminars, workshops, training materials, field manuals, articles, and videos. The application of these end-user products may vary depending on the intended audience, purpose, and topic.

Recycled Binder Availability

MnDOT requests proposals To promote sustainability and ensure adequate performance, there is a need to consider the amount of asphalt binder available from recycled asphalt materials (RAM), including reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS). The use of recycled materials is growing due to economic and environmental benefits, yet there is no accepted method to quantify or account for the effective binder content available in asphalt mixtures from these materials that represent a large fraction as the RAM content increases. The objective of this research project is to demonstrate the benefits of adequately quantifying binder availability from RAM and thus provide guidelines for their efficient use based on laboratory and field performance comparisons of test sections located in different NRRA member states to be defined later.

Join us February 20 at 10 am for a webinar on Sustainable Transportation Solutions. The webinar is free, but registration is required. Presenters will discuss solar snow fences; impacts of shared mobility on infrastructure usage, greenhouse gas emissions, and accessibility; and investigating real storms and the impact of potential climate change adaptations.

MnDOT staff will be participating in more than 30 sessions at the 2025 Minnesota Transportation Conference and Expo from March 19-21 at the St. Paul Rivercenter in downtown St. Paul.  If you’re planning to attend, be sure to check out their sessions!