Category Archives: research

General research posts.

research

Lessons from shuttle project helping shape future of AVs

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Reprinted from CTS News, January 24, 2025

Since October 2022, five self-driving shuttle vans in Grand Rapids, Minnesota—with onboard operators for safety—have offered free, on-demand rides as part of the Minnesota Autonomous Rural Transit Initiative (goMARTI). This pilot project is a collaborative effort between multiple stakeholders and partners to conduct a first-of-its-kind demonstration of self-driving shuttles in a rural setting.

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Automated Vehicle Technology, research, Traffic and Safety

Pavement Markings to Support Automated Vehicles

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Automated vehicles (AVs) using advanced driver assistance systems depend on pavement markings to accurately track roadway lanes. While MnDOT continues to ensure human drivers easily and effectively detect and interpret various pavement markings, the agency also wanted to understand marking designs and characteristics that support AV functions. Field observations in different locations, during the day and at night, using different data collection methods allowed researchers to evaluate the impact of various pavement marking properties on AV lane-keeping functions. Results support MnDOT in producing pavement marking guidance that is responsive to changing needs.

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Policy and Planning, research, Traffic and Safety

Refining Max-Pressure Traffic Signal Control to Improve Traffic Flow

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Effective traffic signal control technologies facilitate optimal traffic flow and travel time. Building on previous research, this project made significant progress toward field implementation of a novel adaptive signal control technology. This research phase demonstrated the max-pressure traffic signal algorithm can successfully integrate into Hennepin County traffic signal hardware and respond to changing traffic conditions in real time, providing confidence to move to the next step and test the system in the field. 

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Materials and Construction, research

Adding fibers to concrete may help create long-lasting roads

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Originally published in CTS News, March 19, 2025

Thin pavements—in which new pavements are constructed over an existing base layer—can be an economical option for low- and moderate-volume roads. However, thinner concrete roads are prone to distress caused by weather and traffic loads. The solution, U of M researchers found, may be to add small synthetic fibers to the concrete.

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research, Traffic and Safety

Comparing the Effectiveness of No Right Turn on Red Sign Types at Traffic Signals

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Preventing right turns on red at traffic signals is a generally effective pedestrian safety measure. But when pedestrians are absent, allowing right turns on red can improve traffic flow. Unlike static signs that prohibit right turns on red, dynamic No Right Turn on Red (NRTOR) signs can be activated when pedestrians are present. Comparing driver compliance with dynamic and static signs indicated that each sign type may have its own benefits. 

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Policy and Planning, Public Transit, research

Examining off-peak transit behaviors to improve transit equity

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Originally published in Catalyst, February 19, 2025

Transit service planning has traditionally focused on peak trips and the needs of “rush hour” commuters rather than off-peak travel. Often, off-peak trips are taken by shift-based essential workers and those who cannot or do not drive. The COVID-19 pandemic further underscored the need for a closer examination of these trips to improve social equity.

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Materials and Construction, research

Understanding the Performance of Road Base Stabilization Additives

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Full-depth reclamation (FDR)—an effective and efficient pavement reconstruction method—can be made even more sustainable by strengthening the road base. Laboratory and field testing of proprietary stabilizers used to amend FDR material illustrated improvements in pavement stiffness and economic benefits over time. New pavement design standards for base stabilizers can guide road engineers in choosing the optimal products for sustainable roads.

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Maintenance Operations, research

New Clear Roads Research: Dashboards for Improving Winter Operations

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From Clear Roads, March 5, 2025

Transportation agencies collect vast amounts of data about their winter operations. Dashboards can help to summarize the information, measure performance, inform decision-making during winter weather events and improve planning for future storms.

This Clear Roads project examined the use of dashboards among transportation agencies to assess current strategies and identify innovative and effective practices. The results offer guidance to transportation agencies that are considering implementing or expanding their dashboard use to enhance winter maintenance operations.

Download the final report and two-page brief: CR 22-05 – Use of Dashboards for Winter Operations, December 2024.

research, Traffic and Safety

New Project: Roundabouts, J-Turns, etc. – Understanding Their Economic Impacts

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Roundabouts and J-turns have consistently shown significant improvements in safety and traffic flow in Minnesota and across the U.S. Still, some community residents and businesses oppose replacing traditional intersections with alternative intersections like roundabouts or J-turns.

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