Reports

This report presents the findings of a research study to identify transferrable lessons from behavior-change and culture-building models that could help inform state efforts to reduce vehicle miles traveled (VMT) by 20 percent by 2050. It includes a literature review of academic and public agency documents as well as interviews and focus groups. This project demonstrates that the similarities between transportation- and non-transportation-focused behavior-change methods can provide important lessons for application of strategies to support the reduction of VMT in Minnesota, providing MnDOT and partners across the state many opportunities to achieve reductions in VMT.

This Research Summary is part of the final deliverable for Report 2025-21, "School start times impact on students walking or biking to school: Safe routes to school."

The Minnesota Department of Transportation (MnDOT) is pleased to present this 2024 City Speed Limit Evaluation Report to the Legislature. As required by 2024 Laws of Minnesota, Chapter 104, Article 1, Section 106, the report summarizes a 2024 evaluation project to help determine the impact of 2019 legislation that allowed cities who met certain criteria to change speed limits within their jurisdiction without a MnDOT speed study or MnDOT approval. Transportation safety remains both a challenge and a high priority for the state. Speeding is a significant contributing factor to fatalities and serious injury crashes, and transportation officials at all levels of government continue to look for strategies that help reduce crash numbers. This report helps identify the cities that implemented speed limit changes since 2019 and presents the results of a before-and-after comparison of speeds and crashes in cities that were included in the study. Summaries of other local, national, and international studies offer additional perspective.

In 2024, Minnesota continued to be a national leader with its connected and automated vehicles (CAV) academic research, industry work, and partnerships with state and local governments. Minnesota’s on-going AV pilot project in Grand Rapids, Minnesota, goMARTI, continues to gain national and international recognition for both its emphasis on AV technology advancements and increasing accessibility for folks with limited transportation options. After a pause in 2023, the Governor’s Council on CAV restarted in 2024 with new members, and was a year rich in accomplishments, making progress on established recommendations. This iteration of the Council strives to be more action-focused and establish clear CAV-based recommendations for Minnesota by looking at what our state needs, where there is opportunity, and where there is risk. The members represent a variety of backgrounds, bringing valuable perspectives which enhance the discussion and provide recommendations that support all Minnesotans.

This report includes information on transit service in Minnesota as required by Minn. Stat. 174.247. In addition, it provides a comprehensive overview of the state’s public transit services by highlighting accomplishments; listing ridership, financial and performance information; and providing a snapshot of every public transit provider in the state. Transit is a key component of Minnesota’s multimodal transportation system, contributing to the health of people, the environment and the economy. In Greater Minnesota, 40 public transit systems in 79 counties offer scheduled transportation service to the public. These transit services are funded through a financial partnership that includes local, state and federal participation. MnDOT strives to make access to quality public transit systems available to citizens statewide. To ensure Minnesota is at the forefront of future transit strategies and financing, MnDOT will work proactively toward its mission to provide the highest quality, dependable multimodal transportation system.

The Minnesota Department of Transportation is pleased to present the 2024 Transportation System Performance Report to the Legislature. As required by Minn. Stat. 174.03, Subd. 12(d), the report presents trunk highway and transportation system performance measures, describes performance gaps, and outlines the agency’s progress toward achieving the state transportation goals established in section 174.01. Minnesota’s transportation system is complex, and to improve performance, MnDOT and its partners regularly assess the system management strategies in place, revisit current performance measures for improvement and evaluate where new performance measures are needed. Although specific performance measures and performance measurement efforts described in the report are in different stages of development – including Transportation Insecurity and those related to the reduction of Green House Gas Emissions and Vehicle Miles Traveled - MnDOT continues to make progress. MnDOT has observed performance gains in several areas over the last year such as improved travel times on MnDOT-operated roadways and decreasing roadway fatalities. However, as use of the transportation system continues to increase following the decreases observed during the COVID-19 pandemic, roadway safety overall continues to be a challenge with the number of serious injuries on Minnesota roadways continuing to increase year-to-year and at the highest point in last five years. Additionally, while still meeting most infrastructure condition performance targets, the percentage of bridges, culverts, and pavement moving into poor conditions have slightly increased. MnDOT is actively assessing infrastructure maintenance and investment strategies to maintain performance and steward transportation resources well.

Some school districts schedule elementary schools with early start times for various reasons. Such start times sometimes necessitate travel before sunrise during winter months. Intuitively, this could potentially conflict with a desire for increased use of active transportation, e.g. from the Safe Routes To School program, to reduce motor vehicle travel and associated traffic congestion from driving students to school. Since prior literature has identified that parents are concerned about child safety around traffic, it is possible that travel before sunrise (where visibility is reduced) would also be a concern to parents and further discourage active transportation. To answer this question, we conducted a stated preference survey of parents about their child's travel choices, asking parents to rank the importance of various factors including travel before sunrise. Due to concerns about whether stated parental preferences would align with actual behavior, we also conducted a revealed preference survey using StreetLight data on travel to elementary schools. Survey distribution and data collection occurred in February in Minnesota, during a period of late sunrise. Overall, the results from all data analyses are aligned. Early school start times were associated with slightly higher use of active transportation in both stated and revealed travel patterns. Parents ranked travel before sunrise only as a moderate concern behind distance, infrastructure, crossing busy roads, and child's age. We did not find data to conclude that travel before sunrise significantly limits use of active transportation.

Asphalt rejuvenators, or recycling agents (RA), are used to incorporate higher amounts of Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) without detrimentally impacting the long-term performance of the pavement. The National Road Research Alliance (NRRA) Flexible Team constructed field test sections as part of a mill and overlay project in northern Minnesota in August of 2019. These field sections included wearing courses with 40% RAP that incorporate seven different RA products, with the dosage determined by the supplier to meet a target extracted and recovered performance grade (PG) of XX-34. In addition to the RA test sections, there were control sections with 40% RAP and 30% RAP (the maximum level allowed on the remainder of this project). The objective of this research project was to evaluate the effectiveness of the seven RA products over time and evaluate their performance as compared to the control mixtures. This was accomplished through a combination of binder (chemical and rheological) and mixture characterization and performance testing using different laboratory aging levels, field core testing, and performance monitoring of the field sections over time. This report documents the results after four years in service with cores taken annually. The study showed that all RAs exhibit improved rheological properties in 1-year field cores. However, the benefits of RA diminish with field aging, and after four years, some RAs show comparable properties with controls. In terms of mixture properties, the inclusion of RA enhances both rheological properties and fracture and fatigue crack resistance initially.

This research summary is part of the final deliverable for Report 2025-22, "Comparison of Compost and Proprietary Soil Amendments for Vegetation Establishment," Published in March 2025.

Post-construction roadside soils often suffer from compaction, low fertility, and poor structure, challenging vegetation establishment and stormwater management. This study evaluates the effectiveness of organic amendments (OAs) and proprietary amendments as alternatives to traditional methods. The study involves greenhouse experiments (pot and mesocosm) and field experiments to evaluate vegetation growth and water quality across different amendment and soil applications. Results show that compost amendments significantly improve vegetation growth, with yard-waste compost outperforming others. Biochar shows early growth potential but requires nutrient supplementation for sustained performance. Proprietary amendments support rapid vegetation establishment, enhanced root density, and reduced nutrient leaching, with Sustane 4-6-4 exhibiting consistent growth across application rates. The field study validates greenhouse findings and shows increased biomass and root density with compost amendments, while proprietary amendments result in high nutrient retention and runoff quality. This study highlights the potential use of OAs and PAs to reduce erosion and support long-term vegetation growth. The findings provide practical guidelines, benefits and implementation steps for managing roadside soils after construction activities.