Warmer winters and more frequent severe rainfall events in Minnesota threaten the integrity and longevity of pavement foundations. Understanding the impacts of saturated pavement layers can help MnDOT design resilient roads. An exploration into the relationship between climate conditions over time and pavement foundation stiffness on test road sections led to the development of a pavement foundation saturation prediction model. The model supports the production of a preliminary geographic information systems (GIS) based pavement vulnerability framework that can guide road engineers in prioritizing maintenance in at-risk areas to ensure strong, durable pavements.
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Transportation challenges for aging rural populations
Reprinted from Catalyst, June 11, 2024
During the past century, a person’s average lifespan has increased dramatically. However, this significant “longevity bonus” has also led to challenges, including how to maintain mobility for an aging population.
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TZD Traffic Safety Hotdish: A Roadmap for Traffic Safety Culture Research and the Road Ahead
Wednesday, July 17, 2024
10:00 – 11:15 a.m. CDT
About the Event
This free virtual event will highlight the Traffic Safety Culture Research Roadmap, recently released by the National Academies of Sciences, Engineering, and Medicine.
Wes Kumfer, who led the creation of the roadmap, will review its development and contents. Jay Otto will share example projects and show how they fit into research on traffic safety culture. Join us to learn how you can identify traffic safety culture research needs and get insights to take back to your own organizational cultures!
Speakers
Dr. Wes Kumfer is an engineering research associate at the UNC Highway Safety Research Center (HSRC) with a focus on crash analysis and workforce development. His primary research interest is traffic safety management through a systems-oriented approach. While at HSRC, Kumfer has worked on pedestrian crash modeling, Safe System implementation, and engineering evaluation. He uses this experience as a member of the Road to Zero Coalition steering group and as an instructor for HSRC’s Road Safety Academy.
Jay Otto is a researcher and co-director for the Center for Health and Safety Culture at Montana State University. He received a bachelor’s and master’s degree in engineering and is fascinated by human behavior, how mindsets and systems influence behavior, and ways of growing cultures within communities and organizations that foster improved health and safety.
Registration
The webinar is free to attend, but registration is required. Once you have registered, you will receive an email confirmation with a Zoom link. The link should not be shared with others; it is unique to you.
Credit
Attendees are eligible for 1.25 Professional Development Hours (PDHs). Download the PDH credit form (PDF) for your records.
More Information
Contact Linda Dolan at ldolan@umn.edu.
Sponsors
This event is offered by the Minnesota Toward Zero Deaths Program and the Minnesota Departments of Health, Public Safety, and Transportation, with funding from the National Highway Traffic Safety Administration. It is hosted by the University of Minnesota’s Center for Transportation Studies.
Evaluating the Traffic Safety Benefits of J-Turns in Minnesota
MnDOT traffic engineers are increasingly installing J-turn intersections on high-speed, multilane expressways to limit potential crash points. An analysis of crash data from intersections before and after the installation of J-turns demonstrated significant safety benefits from this alternative design. MnDOT researchers also explored crash history differences among J-turn intersections with varying characteristics. Consistent with the results from a previous study, this analysis found a clear decrease in fatal and other serious crashes after a J-turn was installed.
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OPERA project: Benefits and limitations of liquid-treated sand
Reprinted from MnLTAP News May 30, 2024
The Cook County Highway Department has been on a mission to combat chloride pollution infiltrating Minnesota’s pristine wilderness. To that end, the department has set a goal for chloride-free winter maintenance, starting from annual road salt use that averages 300 tons. Staff experimented with liquid-treated sand to reduce the use of granular road salt while maintaining road safety.
Continue reading OPERA project: Benefits and limitations of liquid-treated sand
Solutions to Mitigate Dowel/Tie-Bar Propagated Cracking – Phase 1
Cracking and spalling of concrete pavements reduce the service life of the roadway and result in added costs to an agency and disruptions to the traveling public when the damage is repaired.
Continue reading Solutions to Mitigate Dowel/Tie-Bar Propagated Cracking – Phase 1
Development of Mix Designs and Matrix of Materials for MnROAD Low Carbon Concrete Test Site
To address climate change mitigation goals, highway agencies are seeking alternative concrete paving mixtures that have a reduced embodied carbon content (ECC).
The research team first focused on developing a matrix of reduced ECC concrete mixtures to be tested at MnROAD. The 16 concrete mixtures selected for inclusion in the test matrix met minimum engineering requirements to ensure constructability and performance and were approved by MnDOT.
Between July 27 and August 9, 2023, 16 test cells were constructed at the MnROAD I-94 facility to evaluate reduced ECC concrete paving mixtures. The purpose of constructing these cells was to assess the in-service performance, environmental impact, and constructability of various alternative supplementary cementitious materials (ASCMs) that may reduce the embodied carbon content of concrete, while providing an opportunity to assess test results and in-service performance in coming years.
A preliminary environmental assessment showed that most mixtures were expected to have either a similar or lower ECC compared to the control mixture representative of typical MnDOT paving-grade concrete. Quality assurance testing conducted on field-cast specimens revealed generally acceptable results; most of the materials had similar performance compared to the control mixture, but the cells will continue to be monitored.
Understanding Factors That Influence Driver Yielding to Pedestrians
Vehicle speeds, type of pedestrian, road characteristics and other variables can impact whether drivers yield to pedestrians attempting to cross a road at an unsignalized intersection. An analysis of data collected from 18 intersections identified human and site attributes that correlate to higher rates of driver yielding. Knowledge of these potentially influential factors will help local engineers build safer crossings at intersections.
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Enhancing Public Transit with Autonomous Mobility Service to Cover the “Last Mile”
The benefits of public transportation, including reducing individual vehicle use and traffic congestion, aren’t always optimized beyond densely populated urban settings. While transit may extend to more suburban or rural areas, land development patterns can make it challenging for people to reach their destinations by transit alone. Pairing transit with an autonomous mobility service is a potential solution. Researchers assessed transportation needs in a suburban shopping area and developed a system designed to deliver passengers from the end of a transit line to their ultimate destination. Simulations of the autonomous mobility service revealed its potential to increase transit efficiency and reduce individual vehicle use.
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Finding High-Performing Aggregate Bases for Long-Lasting Pavement
Two county roads provided a testing ground for three combinations of aggregate bases and asphalt binders. Results from more than two decades of research and monitoring of pavement test sections validated previous conclusions. A larger gradation aggregate base showed superior performance over the pavement life cycle when compared with the standard aggregate base. Additionally, sections constructed without transverse joints to allow natural thermal cracking outperformed sections with sawn and sealed joints.
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Crossroads 