Roundabouts have been repeatedly shown to reduce fatal and serious crashes, in part by slowing vehicles as they move through intersections. Less was known, however, about how far those speed-reducing effects extend beyond the intersection itself or how they compare with other intersection types. To better understand these upstream and downstream impacts, MnDOT and local transportation agencies worked with investigators to measure vehicle speeds at roundabouts, signalized intersections and all-way stop-controlled intersections. The results showed that roundabouts provide traffic calming benefits beyond the intersection, supporting their continued use as a safe and effective design alternative.
Continue reading Upstream and Downstream Traffic Calming Benefits of RoundaboutsCategory Archives: Traffic and Safety
Research finds pedestrian-focused infrastructure can boost safety
Article reprinted from CTS News, August 12, 2026.
Published MnDOT Report: Behavioral Investigation of Temporary and Permanent Pedestrian Infrastructure
Pedestrian injuries and fatalities have significant personal, societal, and financial impacts, making it crucial to identify effective strategies to improve pedestrian safety. A research project by the UMN’s Human Factors Safety Laboratory (HFSL) evaluated the effectiveness of both temporary (i.e., quick-build) and permanent pedestrian-focused intersection features, such as curb extensions and pedestrian refuge islands. Researchers sought to understand how these features changed pedestrian and driver behavior — and how that affected safety.
Minnesota, in line with nationwide trends, saw an increase in pedestrian deaths between 2013 and 2022 (from 1.55 to 2.33 deaths per 100,000 nationwide). Similar high-income countries generally experienced a decrease in pedestrian deaths in the same period. “This remains a hot-button topic for research in the traffic safety space,” said HFSL research associate Curtis Craig, lead investigator on the project and CTS scholar, in a webinar discussing the research. The project was sponsored by the Minnesota Department of Transportation and the Minnesota Local Road Research Board.
Several unique factors make U.S. roadways especially challenging for pedestrians. “The high incidence of large trucks and SUVs makes it more difficult to see pedestrians, and any impact would be more severe because of the greater mass and geometry of the front grills on those vehicles,” Craig said. “There’s also simply a large preponderance of high-speed, multi-lane roads, which is a high-risk factor for pedestrians and drivers.”
Pedestrian-friendly infrastructure strategies aim to reduce those risks. With guidance from Minneapolis’s Vision Zero 2023–2024 pedestrian safety plan, researchers identified 12 intersections in Minneapolis and St. Paul to study before and after the installation of quick-build pedestrian infrastructure and concrete infrastructure. Quick-build infrastructure includes temporary or plastic features, such as bollards replicating bump-outs and sidewalk extensions. The goal of the study was to compare the safety influence on driver behavior of these quick-build features with those of permanent concrete infrastructure.
The study evaluated a mix of signalized and unsignalized intersections with temporary and permanent infrastructure features in a variety of income areas and with various levels of pedestrian and vehicle traffic. The team recorded driver behavior in pass-through and right-turn intersections. Data was collected in staged and natural pedestrian crossings using both in-person observations and video to record driver speeds, stops, and pedestrian behavior. The video footage was analyzed with the help of artificial intelligence algorithms.
The study found that whether permanent or temporary, the presence of the installations generally improved the rates of drivers stopping for pedestrians and led to a small but significant decline in traffic speeds at intersections. Temporary median refuges reduced the average speeds of drivers in free-flowing traffic at both signalized and unsignalized intersections. Since high driver speed is associated with a higher likelihood of pedestrian fatalities and higher injury severity, this is an especially meaningful benefit, Craig noted.
However, using flexible delineators as temporary curb extensions slightly reduced the likelihood of drivers stopping for pedestrians compared to permanent infrastructure, particularly at signalized intersections. The researchers noted a decline in stopping rates, for right-turning drivers at signalized intersections outfitted with temporary curb extensions, while the permanent, concrete curb extensions appeared to perform slightly better. The researchers speculated that the presence of bollards or other features surrounding the temporary infrastructure created a distraction, or “clutter,” that diverted drivers’ attention away from pedestrians as they navigated the intersection turn. “It’s a more visually complex environment, with more cars and more pedestrians to look out for,” Craig said.
The flexible delineators used cost between $30 and $100 each plus labor for installation, and most intersections require 12 delineators. Meanwhile, permanent concrete extensions cost about $18,000 each (or more if installation requires interaction with the sewage system) and median islands cost as much as $55,000. However, the study emphasizes that fatal pedestrian crashes have a tremendous cost. Beyond devastating personal and societal impacts, researchers point to a 2020 assessment by the U.S. Centers for Disease Control and Prevention that tallied more than $68 million in medical and work-loss costs related to pedestrian fatalities.
No two intersections in the study could be considered identical; the presence or lack of on-street parking, construction, and variations in pedestrian behaviors influenced each crossing. Craig said that future engineering projects considering the use of quick-build infrastructure need to weigh the many variables that define each intersection. Ultimately, when transportation infrastructure prioritizes pedestrians, public safety improves on Minnesota’s streets.
—Amy Goetzman, contributing writer
Related MnDOT research
Many MnDOT and LRRB projects have looked at pedestrian safety. Here is a sample of them.
- Improving Safety for People Walking and Biking at Roundabouts
- Evaluating pedestrian considerations for transit advantage at roundabouts
- Rural Intersection Enhancement and Driver Behavior Study
- Comparative Analysis of Grade-Separated Pedestrian Infrastructure and At-grade Treatments
- Multi-Method Investigation of Pedestrian Safety Impacts of Right-Turn Lanes
- Guidelines for Safer Pedestrian Crossings: Understanding the Factors that Positively Influence Vehicle Yielding to Pedestrians at Unsignalized Intersections
- Pedestrian Safety and Accessibility Best Practices for Channelized Right Turn Lanes
- Pedestrian Engineering and Enforcement at Signalized Intersections
- Enhancing Pedestrian Experiences at Roundabouts
- Traffic Safety Evaluation of Pedestrians and Bicyclists at Roundabouts in Minnesota
- Pedestrian Crossings and Safety on Four Anishinaabe Reservations in Minnesota
New Project: Does lowering speed limits reduce driver speeds on urban streets?
In 2019, the Minnesota Legislature passed a law reducing barriers for cities to systematically lower speed limits. The City of St. Louis Park followed this guidance by reducing speed limits in 2021, but initial speed data collected before and 6–8 months after the changes showed little to no short‑term impact. Because driver behavior is habitual and may change slowly, advocates suggest that greater reductions in operating speeds may emerge over time, highlighting the need for repeat monitoring between 2025 and 2027.
This study aims to evaluate whether longer‑term changes have occurred 2–4 years after the initial reductions, while also examining other Minnesota agencies that have implemented or are considering reduced speed limits. The research will gather both measured and anecdotal data, assess “after” speed conditions where needed, and analyze how effectiveness varies based on roadway characteristics and any accompanying speed reduction countermeasures. These efforts address lingering questions about how speed limit changes influence driver behavior and roadway safety over time.
Understanding speed is critical because it directly affects the safety of all road users. According to Minnesota Motor Vehicle Crash Facts 2022, speeding was the leading cause of traffic fatalities, contributing to 130 of the state’s 444 deaths. By identifying agencies that have reduced speed limits, evaluating short‑ and long‑term impacts, and analyzing site‑specific factors, this research will produce guidance to help Minnesota road agencies assess and implement effective speed limit reductions.
“There is renewed interest in lower speed limits on municipal-type streets,” said Victor Lund, traffic engineer with St. Louis County’s Public Works Department. “The objective of this research is to better understand the intersection of speed limit policy, driver behavior and safety, which will result in guidance to better inform policies, practices and speed limits that support safer streets.”
The Objectives:
- Identify local agencies in Minnesota that have implemented reduced speed limits or may consider implementation along with any speed reduction countermeasures that have been implemented with the reduced speed limits.
- Evaluate the short-term and long-term effects of speed limit reductions implemented in Minnesota through the collection and analysis of speed data.
- Assess how these effects vary based on site characteristics or speed reduction countermeasures that were implemented in coordination with the reduced speed limit.
- Based on the findings, develop a summary document to aid Minnesota road agencies in assessing potential speed limit reductions.
Project Details:
- Estimated Start Date: 06/25/2025
- Estimated Completion Date: 06/30/2027
- Funding: MnDOT and Local Road Research Board
- Principal Investigator: Peter Savolainen
- Co-Principal Investigators: Tim Gates
- Technical Liaison: Victor Lund
Details of the research study work plan and timeline are subject to change.
To receive email updates about this project, visit MnDOT’s Office of Research & Innovation to subscribe.
Evaluating the Use of a Common Alternative Deicer
When temperatures fall below 15 degrees Fahrenheit (F), salt loses its effectiveness at melting snow on roads. To accommodate lower temperatures, transportation agencies often combine an alternative deicer with salt brine to treat roads and return them to an appropriate level of service. This project investigated the most common alternative deicer used in Minnesota to provide guidance to state and county winter maintenance managers about its application at different concentrations and temperatures.
Continue reading Evaluating the Use of a Common Alternative Deicer
New Project: Can Enhancing Color on Dynamic Message Signs Improve Clarity and Safety?
The majority of MnDOT’s dynamic message signs (DMS) are equipped to produce full color/full matrix messaging. Current signage regulations refer to retroreflective colors for static signs, but MnDOT aims to extend and modify existing standards and guidelines by exploring differences between static signs and DMS.
This research will systematically explore and optimize the use of different colors and color-coding schemes in DMSs to resemble the retro-reflectivity of static signs and examine how legibility, visibility, and effectiveness can be improved. Optimizing DMS colors to mimic retroreflective static sign colors and adapting them to myriad environmental conditions, MnDOT can realize reduced driver distractions, improved information comprehension, and increased safety. The project will also support improved decision-making processes by providing evidence-based guidance for future standards and practices for MnDOT beyond.
A pilot study will be conducted to assess the recommended color settings against benchmark real-world conditions. Empirical data on the new configurations will measure their performance, confirm their effectiveness and identify any adjustments required prior to broader implementation.
“Not all color is created equal! As illustrated in the three graphics below, federal standards for reflective sheeting and striping, NEMA standards for colors, and the triangle of visible light LED lights can produce do not correspond,” said Terry Haukom, senior engineer with MnDOT’s Regional Transportation Management Center. “This variance has caused the signage industry to display colors that meet federal standards but do not look correct to the human eye. In addition to exploring this incongruity, our research is focused on understanding and comparing what typical travelers understand and expect when viewing traffic information on the web, and whether the travel time numbers displayed on our signs can give drivers a better understanding of the travel time to the listed destination if it was displayed with a color scheme that leveraged web-based maps.”
The Objectives:
- Standardize the emitted colors from MnDOT’s DMS according to NEMA TS4 and MUTCD specifications, ensuring they match the retroreflected colors of static signs and align with current LED capabilities
- Document the public’s perception of optimum color if different from standards based on human factors feedback
- Document the public’s perception of dark pixel around graphics on emitted colors on DMS
- Research and document the public’s perception of emitted colors on DMS compared to static sign messages, and explore the incorporation of web-based travel time map colors to enhance visibility and clarity, especially with colors like amber
Project Details:
- Start Date: 06/2/2025
- Estimated Completion Date: 04/30/2027
- Funding: MnDOT
- Principal Investigator: Ali Zockaie
- Co-Principal Investigators: Mehrnaz Ghamami, Peter Savolainen, Kakan Dey
- Technical Liaison: Terry Haukom
Details of the research study work plan and timeline are subject to change.
To receive email updates about this project, visit MnDOT’s Office of Research & Innovation to subscribe.
CTS Webinar: How Infrastructure Shapes Driver Behavior and Pedestrian Safety
Tuesday, May 19, 2026, 12:00–1:30 pm Virtual
About the Event
Improving pedestrian safety requires a deeper understanding of how people interact with roadway design and infrastructure. This webinar will highlight two recent research efforts examining how transportation infrastructure influences driver behavior and pedestrian safety outcomes.
Curtis Craig, a research associate in the Human Factors Safety Laboratory, will present findings from two complementary studies examining infrastructure at intersections. The first study explored how right turn lane configurations affect pedestrian safety using a combination of behavioral analysis and multiple research methods. The second project examined how drivers and pedestrians respond to different infrastructure treatments and how those designs influence behavior in real-world environments.
These study findings offer transportation agencies, planners, and engineers practical considerations as they work to create safer and more accessible pedestrian environments.
Registration and More
This webinar is free, but registration is required. Visit the event web page to register and for more information.
Related Reading
- Behavioral Investigation of Temporary and Permanent Pedestrian Infrastructure
- Evaluating the Safety Impacts of Select Pedestrian Infrastructure
- Multi-Method Investigation of Pedestrian Safety Impacts of Right Turn Lanes
- Pedestrian Safety Impacts of Dedicated Right-Turn Lane
- Crossroads: Pedestrian Safety Impacts of Dedicated Right-Turn Lanes
Active Research by Curtis Craig
Analysis and Risk Management of Motorcycle, Bicycle, and Pedestrian Crashes in Minnesota
Alerting Drivers Dangerously Approaching Work Zones
Motorists driving dangerously in work zones present a safety risk to workers and themselves. Alerting these drivers about their driving behavior before they reach the work zone could reduce the number of work zone crashes and enhance work zone safety. This project developed and evaluated the performance of a device that provides audio and visual alerts to drivers whose vehicles are approaching work zones at a high speed and on a dangerous trajectory.
Continue reading Alerting Drivers Dangerously Approaching Work Zones
Evaluating the Safety Impacts of Select Pedestrian Infrastructure
To enhance pedestrian safety at intersections, transportation agencies may install temporary or permanent infrastructure such as curb extensions or pedestrian refuge islands. While more permanent infrastructure with concrete is generally considered effective, specific details about temporary infrastructure with flexible delineators (or bollards), such as installation, use and safety impact, would be valuable to optimize cost-effectiveness. This project evaluated both temporary and permanent pedestrian infrastructure at crossing sites to measure the effects on pedestrian safety and driver behavior.
Continue reading Evaluating the Safety Impacts of Select Pedestrian Infrastructure
Pedestrian Safety Impacts of Dedicated Right-Turn Lanes
While research has found that right-turn-only, or dedicated right-turn lanes, at intersections reduce traffic delays and vehicle crashes, their impact on pedestrian safety has been unclear. To better understand these impacts for future intersection design and countermeasure considerations, this project investigated driver response to pedestrians in or near crosswalks at dedicated right-turn lanes.
Continue reading Pedestrian Safety Impacts of Dedicated Right-Turn Lanes
CTS Webinar: A New System to Report School Bus Stop-Arm Violations
Wednesday, December 10, 2025
11:30 a.m.–1:00 p.m. CST
Zoom Virtual
About the Event
School bus stop-arm violations by motorists pose a serious risk to children. A new University of Minnesota study investigated the existing violation reporting ecosystem, finding issues like underreporting, underenforcing, and significant workflow inefficiencies and barriers across all stakeholder groups.
To address these systemic barriers, study researchers concluded that a centralized statewide online portal is needed to streamline communication, simplify data access, and standardize reporting. They also provided near-term recommendations until this comprehensive solution can be developed.
Join this webinar to learn about the research findings and proposed short- and long-term recommendations for improving the reporting system, with the goal of making bus stops safer for children across Minnesota and beyond
Crossroads 