Transportation research is often about numbers. In a recent study, however, U of M researchers looked beyond the data to hear the transportation experiences of real people from underserved communities in Minnesota.
Continue reading Personal Stories Illustrate Transportation Inequities in Minnesota
New Project: Development of Process to Lower Global Warming Potential of Construction Materials
Advances in science of life cycle assessment (LCA) have set the stage to develop methods that meet global warming potential (GWP) reduction targets for construction materials, specifically, using instruments such as Environmental Product Declarations (EPD).
Continue reading New Project: Development of Process to Lower Global Warming Potential of Construction Materials
Preparing for the Future of CAVs: Cybersecurity, Winter Weather Research
Connected and automated vehicles (CAVs) hold promise for improving transportation operations—but could also provide pathways for “malicious actors” to compromise vehicle security, said Rafael Stern, a U of M assistant professor, in a recent CTS webinar.
Continue reading Preparing for the Future of CAVs: Cybersecurity, Winter Weather Research
New Project: Assessing a New Tool for Early Detection of Endangered Turtles on Proposed Transportation Projects
As turtle populations decline worldwide, increased protections (e.g. United States Endangered Species Act) yield increased regulatory burdens. As a consequence, monitoring of imperiled turtle species is imperative to understand both their extant distributions, but also to ensure regulatory compliance.
However, conventional methods for surveying turtles are frequently costly, time consuming, require taxonomic expertise, and unlikely to yield detections without repeated visits. And these burdens are exacerbated when sampling rare, threatened, or endangered (RTE) species. In these instances, innovative technological advances may overcome these limitations, ultimately streamlining monitoring.
Continue reading New Project: Assessing a New Tool for Early Detection of Endangered Turtles on Proposed Transportation Projects
Evaluating Metrics and Performance to Advance Transportation Equity
Ensuring Minnesota’s transportation network does not create barriers or hardships for underserved or underrepresented communities is imperative. But knowing if the agency is planning and administering programs or projects equitably can be challenging to assess. New research suggests improved performance measures and strategies to support agency efforts to advance equity across the agency’s responsibilities.
Continue reading Evaluating Metrics and Performance to Advance Transportation Equity
Evaluating MnDOT’s Turfgrass Seed Variety List and Approval Process
As climate conditions change and seed development processes advance, some grass varieties may perform better than others. New research will allow MnDOT to update its approved turfgrass list and ensure it remains up to date with the most effective varieties.
Continue reading Evaluating MnDOT’s Turfgrass Seed Variety List and Approval Process
Comparing the Cost-Effectiveness of Asphalt Binders for Local Roads
Asphalt pavements with polymer-modified binders (PMBs) perform better than pavements with unmodified asphalt binders. While pavements with PMBs may cost more initially, performance is improved in the long run. In a recent study, researchers compared the performance and life cycle costs of modified and unmodified binders and found that modified binders are more cost-effective, even for local low-volume roads.
Continue reading Comparing the Cost-Effectiveness of Asphalt Binders for Local Roads
Future of Mobility: Urban air mobility
June 26, 2023
What’s next in transportation?
The Future of Mobility series collects the perspectives of top U researchers and other national experts. In 17 articles, the authors scan the horizon and reflect on critical transportation topics. Each article recommends action steps for public officials and policymakers.
CTS is highlighting the articles over the course of the year. This month, we explore two aviation-related articles: Safety and Urban Air Mobility by Demoz Gebre-Egziabher and Advanced Air Mobility by Susan Shaheen and Adam Cohen.
Autonomous aircraft and drones that can move people and goods in new ways are coming to our cities, writes Gebre-Egziabher. Often referred to as urban air mobility (UAM), these new transportation concepts are the flying equivalent of the autonomous car—and they raise just as many important questions about safety, use, and operations. Local communities and agencies are stakeholders that must have a say in safety and provide clear guidance to those developing technologies for UAM, he says.
Shaheen and Cohen write that aviation is undergoing rapid change around the world. A variety of technological advancements and industry investments in electrification, alternative fuels, automation, vertical take-off and landing aircraft, uncrewed aircraft systems, and air traffic management are enabling innovations in aircraft designs, services, and business models. They recommend driving the industry forward with an emphasis on social and environmental benefits, including humanitarian, aeromedical, and emergency response.
New Project: Assessing Methods to Mitigate Cognitive and Physical Declines That Influence Driving Performance of Older Drivers
Supporting older drivers to safely age in place as they experience age-related declines is important as many Minnesota drivers are reaching retirement age. Minnesotans, 65 years and older, are expected to represent 20% of the state population by 2025, with an overall increase of 122% from 2010-2040. While older drivers are generally safe drivers, those aged 75-85 face the highest risks from injury.
Continue reading New Project: Assessing Methods to Mitigate Cognitive and Physical Declines That Influence Driving Performance of Older Drivers
With new signal timing method, Twin Cities traffic could flow more smoothly
Reprinted from Catalyst, May 12, 2023.
Eliminating intersection bottlenecks is one of the most persistent and difficult challenges for traffic engineers. A new mathematical theory called “max-pressure signal control” has been proven to achieve maximum throughput for entire city road networks, but it has not yet been used in practice. In a new study, U of M researchers brought the theory several steps closer to real-world use and found that it could offer many benefits to Minnesota road users.
“For most intersections and demand periods, we found that max-pressure control offered significant improvement over current signal timings,” says Michael Levin, an assistant professor with the Department of Civil, Environmental, and Geo- Engineering. “Large reductions in delay—sometimes over 50 percent—suggest that this new method of signal timing could achieve higher throughput during peak demand and be more responsive to queues.”
To achieve these findings, researchers began by addressing some aspects of max-pressure signal timing that would make it difficult to implement in a real-world setting. First, researchers addressed its assumption that all roadways had separate turning lanes by adapting the mathematical model to accommodate mixed travel lanes.
Another drawback of the original formula is that the signal control doesn’t operate on a cycle; this could cause long wait times when demand is uneven and make the signal cycle unpredictable for both drivers and pedestrians.
“To solve this issue, we modified the formula to include a maximum waiting time and require that the phase selection follows a cycle,” Levin says. “This allows traffic engineers to create an ordered set of phases for each intersection.”
Once the updated version of max-pressure control was developed, researchers tested it in simulations of two corridors in Hennepin County, Minnesota. The simulations revealed numerous potential benefits including reduced environmental impacts and reduced road user costs resulting from travel time savings and lower fuel costs.
“The findings show that our new max-pressure control formula will reduce the average queue length during peak hours and that vehicles will not wait as long at intersections,” Levin says. “We can also predict higher throughput and faster vehicle speeds, all of which will mitigate congestion and improve quality of life.”
In addition, a cost-benefit analysis shows that the total value of travel time savings is considerably larger than the cost to implement max-pressure control.
The project’s success led researchers to explore the possibility of a real-world pilot project with available traffic signal hardware. They found that the traffic signal technology currently used in Hennepin County could be upgraded to support a pilot study, laying the groundwork for a future real-world test of this promising new signal timing method.
The project was funded by the Minnesota Local Road Research Board (LRRB). Phase two of the work, also funded by the LRRB, is underway.
Writer: Megan Tsai
More Information
- MnDOT Phase I Project page
- Final report, Phase 1
- Phase 2 Project Page
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