Category Archives: Research

General research posts.

MnDOT Chooses EasyMile for Autonomous Shuttle Bus Project

ST. PAUL, Minn. – The Minnesota Department of Transportation chose EasyMile, a France-based company specializing in driverless technology, to lead its autonomous shuttle bus pilot project. MnDOT announced in June it will begin testing the use of an autonomous shuttle bus in a cold weather climate.

“We’re excited to partner with EasyMile to help MnDOT test autonomous technology,” said Jay Hietpas, MnDOT state traffic engineer and project manager. “Their expertise will help us learn how these vehicles operate in a winter weather environment so we can advance this technology and position MnDOT and Minnesota as a leader.”

EasyMile, which has a location in Colorado, has conducted driverless technology cold weather tests in Finland and Norway. Minnesota will be their first cold weather test site in the U.S. EasyMile will use its EZ10 electric shuttle bus that has already transported 160,000 people more than 60,000 miles in 14 countries. The shuttle was tested in various environments and traffic conditions. During these tests, the shuttle operated crash-free.

The shuttle operates autonomously at low speeds on pre-mapped routes. It can transport between six and 12 people.

Initially, it will be tested at MnROAD, which is MnDOT’s pavement test facility. Testing will include how the shuttle operates in snow and ice conditions, at low temperatures and on roads where salt is used.

Testing is scheduled to start in November and go through February 2018. The shuttle will also be showcased during the week of the 2018 Super Bowl.

Hietpas said 3M will also be a partner in the project so the company can research various connected vehicle concepts including sensor enhancement and advanced roadway safety materials. When optimized, these materials would aid in safe human and machine road navigation.


Read more about the autonomous shuttle bus pilot project:


Related MnDOT research:

New recommendations aim to help roadside turfgrass thrive

Keeping Minnesota’s roadsides green is about more than just aesthetics—healthy turfgrass can improve water quality, reduce erosion and road noise, and provide animal habitat. However, harsh conditions such as heat, drought, and salt use can make it difficult for roadside turfgrass to thrive.

In 2014, as part of a study funded by the Minnesota Local Road Research Board (LRRB), researchers in the University of Minnesota’s Department of Horticultural Science identified a new salt-tolerant turfgrass mixture that could be used on Minnesota roadsides. But, when MnDOT began using the mixture, called MNST-12, the agency experienced a series of installation failures.

Now, led by Professor Eric Watkins, the research team has identified new best management practices for installing and establishing this type of salt-tolerant turfgrass.  The study, funded by the LRRB, specifically focused on watering practices, soil amendments, and planting date for both seed and sod.

“Newer improved seed or sod mixes like MNST-12 may have differing requirements for successful establishment compared to other species or cultivars that contractors and other turf professionals are more familiar with,” Watkins says. “Since all of these management practices are prescribed—or not prescribed—in the MnDOT specifications, generating data that can inform future specifications is a valuable outcome of this work.”

The study, which was conducted over several years, included experiments on how water should be applied to new MNST-12 turfgrass installations, the use of soil amendments at the time of establishment, and the effect of the seeding or sodding date on the success of a new planting.

Researchers tested turfgrass watering requirements using an automated rain-out shelter. Photo: Matt Cavanaugh

Based on their findings, the researchers recommend these changes to MnDOT specifications:

  • No soil amendments are necessary, but adequate seedbed preparation is important.
  • Seeding is preferred to sodding between August 15 and September 15.
  • Sodding can be permitted throughout the year, but only if the installer is able to supply frequent irrigation.
  • When watering in sod, attention should be given to the species being used and local rates of evapotranspiration (evaporation from both the soil and plant leaves). Sod installers can anticipate using between 100,000 and 170,000 gallons of water per acre to ensure a successful establishment.
  • Sod can be mowed as soon as sufficient root growth prevents an operator from manually pulling up pieces by hand, but it should not be mowed if wilting from heat or drought.

Currently, the researchers are using the results of this project to develop methods for educating and training stakeholders, including turfgrass installers, on these best management practices. They are also developing systems that could be used by installers in the field to help maximize the success rate of turfgrass installations.

“These best management practices can help limit installation failures and reduce maintenance inputs for future installations, providing both an economic and environmental benefit,” Watkins says.

“The knowledge and improved specifications we gained through this research will allow us to make our contractors more successful, which makes MnDOT successful,” says Dwayne Stenlund, MnDOT erosion control specialist. Because local agencies often rely on these MnDOT specifications as a guide for their projects, they will also benefit from the improved practices.

Stenlund also says the new specifications—especially those related to watering requirements—could allow for a clearer understanding of the true cost and value of turfgrass installation and maintenance work, which could ultimately improve the accuracy of the project bidding process.

In another project, the research team is exploring other turfgrass stresses, such as ice cover and heat. They are also testing additional turfgrass species and mixtures in an effort to continue improving MnDOT specifications for roadside turfgrass installations.

Developing a Uniform Process for Quantifying Research Benefits

Researchers worked with MnDOT technical experts to develop a method for identifying the financial and other benefits of MnDOT research projects. They developed a seven-step process for quantifying benefits and applied the process to 11 recent MnDOT research projects. Results showed that these projects were yielding significant financial benefits.

“We have very high expectations for the research dollars we spend,” said Hafiz Munir, Research Management Engineer. “MnDOT Research Services & Library. Following this project, we now ask investigators to tell us upfront what benefits their research could achieve, and we have improved our internal process for tracking and assessing the quantifiable benefits.”

“A lack of before-research data on the transportation activities being studied may be the biggest challenge to quantifying the benefits of research on Minnesota transportation needs. Other states are also trying to do this, but they use informal or ad hoc processes,” said Howard Preston, Senior Transportation Engineer, CH2M Hill.

What Was the Need?

MnDOT Research Services & Library manages more than $10 million in research each year, with 230 active projects covering everything transportation-related — from subgrade soils to driver psychology. Communicating the value of these research investments is an important component of transparency in government, a core interest in Minnesota.

Quantifying the benefits of research projects that lead to innovations such as new and improved materials, methods and specifications is important to MnDOT and its customers. However, because MnDOT conducts such a wide variety of research projects, it is challenging to assess the benefits that will, when applied in practice, result in quantifiable savings of time, materials or labor, or that will lead to safer roads and fewer traffic crashes.

What Was Our Goal?

MnDOT undertook this project to develop a more systematic method for identifying and measuring the financial and other benefits of its research in relation to the costs. The goal was to develop an accessible, easily applicable process that could be pilot-tested on a selection of MnDOT research projects from recent years.

What Did We Do?

MnDOT provided researchers with documents about benefits quantification practices to review and with the results of a survey of state departments of transportation on their approaches to quantifying research benefits. This review identified few states that had developed formal guidelines for assessing research benefits, and none were easily applicable to MnDOT procedures.

After reviewing the findings and consulting with MnDOT technical experts, investigators recognized that any procedure for quantifying benefits should be rooted in current MnDOT research processes. Researchers worked with a number of MnDOT offices to identify research projects that were suitable for assessing financial and other benefits from research results.

In addition to identifying projects for benefits analysis, investigators and MnDOT identified categories of benefits and developed a seven-step process for gathering and organizing cost data for various project types, applying a benefits assessment process and comparing benefits to research cost.

What Did We Learn?

The research team performed benefit-cost assessments for 11 projects. Six of the assessments had high confidence levels. One challenge in developing a uniform process included refining the complex range of cost input categories, input data options and research objectives associated with the research projects. Assembling and organizing before-research data, even for fairly simple maintenance activities, proved particularly challenging and impeded the development of benefits assessment processes.

Investigators developed a user guide, a training presentation and a quantification tool — a complex set of spreadsheets for inputting data and calculating comparative benefits. The quantification tool should eventually develop into a user-friendly software package or Web interface.

SAFL baffle
The SAFL baffle was developed in a MnDOT research project for $257,000. Researchers determined that its use across Minnesota would save taxpayers $8.5 million over three years.

Based on the analysis of cost and savings data, the 11 research projects showed significant benefits. In one 2012 project, investigators developed an inexpensive baffle that is inserted into stormwater sumps and slows the flow of water in and out, allowing more contaminated sediment to settle rather than being carried into streams and lakes. Re-search to develop the baffle, at the University of Minnesota St. Anthony Falls Laboratory (SAFL), cost $257,000. The cost to purchase and install the baffle is about $4,000 in Minnesota compared to $25,000 for more traditional stormwater mitigation solutions. Use of SAFL baffles in Minnesota is projected to save the state about $8.5 million in equipment, installation and environmental costs over a three-year period.

In total, the research cost of $1.98 million for the 11 projects analyzed is expected to save an estimated $68.6 million for MnDOT and Minnesota cities and counties over a three-year period, for a benefit-to-cost ratio of about 34-to-1. The expected savings will be enough to pay for the research budget for six or seven years.

What’s Next?

MnDOT has added quantification-of-benefits elements to its research proposal evaluation process, and since late 2015 has asked potential principal investigators to supply information on the current costs of the activities they propose to study and improve.

Since 2016, research project awards have included a request that investigators develop quantifiable data resulting from their research activity. The awards offer additional funds for that work. Investigators now provide a brief memorandum within the first 90 days of the project describing how they will quantify benefits, and in some cases presenting preliminary data. At the end of the project, these investigators describe their quantification process and results. MnDOT has tracked this information in a database, finding that about three out of every four projects show potential to yield quantifiable benefits.


This post pertains to Report 2017-13, “Development of a Process for Quantifying the Benefits of Research,” published July 2017. 

Reducing speeds to improve safety for work-zone flaggers

When drivers approach a roadway work zone at high speeds, they put the lives of work-zone flaggers at risk. To keep flaggers safe on the job, U of M researchers are looking for better ways to capture drivers’ attention—and compel them to slow down—as they approach flagger-controlled work zones.

Kathleen Harder, director of the Center for Design in Health, and John Hourdos, director of the Minnesota Traffic Observatory, identified and tested new work-zone warning elements to more effectively capture and sustain driver attention. The project was funded by MnDOT and the Minnesota Local Road Research Board.

The project began with a simulator study in which participants completed three drives, each featuring a work zone with different warning treatments. One condition was a traditional four-sign configuration currently used to warn drivers approaching work zones. The other two conditions featured a variety of new elements, including signage with new messaging such as  a “one-lane road ahead” sign with flashing LED lights, a dynamic speed warning sign equipped with a loud warning horn that sounded if drivers exceeded the speed limit, and portable rumble strips.

“Overall, we found that the new set of elements is more effective than the elements currently used to reduce driving speeds on the approach to a flagger-controlled work zone,” Harder says.

Although adding LED lights to the one-lane road sign had no significant effect on drivers’ speeds, findings indicated that the dynamic speed sign coupled with the horn was more effective than the dynamic sign alone.

To test these new elements under real-world conditions, the researchers conducted field tests evaluating two configurations in Minnesota work zones. The first configuration followed the minimum standards outlined in the Minnesota Manual on Uniform Traffic Control Devices. The second deployed signs employing new messaging and attention-getting devices, including a dynamic speed warning sign, horn, and rumble strips.

Findings showed that the combination of the dynamic speed warning sign and the horn successfully reduced the overall speed of vehicles approaching the work zone. The portable rumble strips did not cause any significant speed reduction, but this may have been related to their location downstream from the dynamic speed sign and horn.

“Our findings reveal that the new set of elements designed to capture driver attention—including new messaging, a dynamic speed trailer, and horn—had a significant influence on reducing driver speed,” Harder says. “The experimental layout practically eliminated high-speed outliers and successfully reduced the approach speed to the flag operator.”

Seven Pilot Projects to Change Transportation Practice in Minnesota

Roadside fencing that protects endangered turtles, a toolkit for identifying potentially acid-producing rock and a device that could save MnDOT $200 million a year in pavement damage are just a few of the advancements that MnDOT hopes to make in the near future, thanks to seven recently funded research implementation projects.

Each spring, the governing board for MnDOT’s research program funds initiatives that help put new technology or research advances into practice. This year’s picks aim to improve the environment, reporting of traffic signal data, notification of lane closures and the design and quality of pavements.

Here’s a brief look at the projects (full proposals here):

Protecting the Environment and Wildlife

  • To avoid the leaching of potentially acid-generating rock during excavation projects, MnDOT hopes to develop a GIS-based risk-screening tool that identifies areas where PAG rock might be encountered. Guidance will be developed for identifying and handling PAG rock.

Found in bedrock throughout the state – especially northern Minnesota, PAG minerals can release acid upon contact with air or water, a danger to aquatic and human life.

“Anytime we dig, there is the potential to expose this stuff,” said Jason Richter, chief geologist.

  • Reducing roadway access for small animals, including endangered turtles, is a priority for MnDOT and the Minnesota Department of Resources. MnDOT will analyze the effectiveness of different types of small animal exclusion fences tried across the state and develop a standard set of designs for future projects.
Improved Reporting of Traffic Signal Data
  • A centralized hub of traffic signal data could benefit future vehicle-to-infrastructure (V2I) applications and assist with the modeling of transportation project impacts. Methods and tools will be developed for a regional database of intersection control information that extracts data from MnDOT’s recently acquired Central Traffic Signal Control System and soon-to-be adopted Signal Performance Measure application.
Real-Time Notice of Lane Closures
  • In this pilot project, 20 MnDOT arrow board messages will be equipped with technology that automatically reports lane closures on 511 and highway message boards, providing more timely motorist notification.
Longer-Lasting Roads and Improved Quality Control
  • This summer, a new quality assurance device called the Rolling Density Meter will be deployed on several pavement projects, eliminating the need for destructive sample cores.
    “This is the ultimate in compaction control,” said Glenn Engstrom, Office of Materials and Road Research director. If contractors obtain the right level of density when paving asphalt roads, MnDOT could eliminate $200 million per year in premature road failure.
  • In 2018, MnDOT plans to require Intelligent Compaction (a pavement roller technology that reduces workmanship issues) on all significant asphalt projects. A vehicle-mounted mobile imaging device will be piloted that collects necessary supportive roadway alignment data, without the need for survey crews.
  • Upgrades to MnDOT’s pavement design software, MnPAVE, (incorporating recycled unbound and conventional base material properties) will help increase the service life of Minnesota roads.

New work-zone warning app featured on KARE 11

A new app that sends warning messages to drivers as they approach work zones was featured on KARE 11 News on Thursday. The app was developed by U of M researchers in a project sponsored by MnDOT.

The story aired as part of KARE 11’s #eyesUP campaign to end distracted driving.

The app works by pairing with Bluetooth low-energy tags placed in work zones, triggering audio warnings in smartphones that are within their range. This allows drivers to get a warning message without having to look down at their phones—or at warning devices such as changeable message signs outside their vehicles. And if a driver is being distracted by their phone, the app will interrupt whatever they are doing to provide a warning that a work zone is up ahead.

U of M researchers Chen-Fu Liao and Nichole Morris, who worked on the project, are interviewed in the story, along with Ken Johnson, work-zone, pavement marking, and traffic devices engineer at MnDOT.

New manual helps agencies count bike, pedestrian traffic

As part of an ongoing effort to institutionalize bicycle and pedestrian counting in Minnesota, MnDOT has published a new manual designed to help city, county, state, and other transportation practitioners in their counting efforts.

The Bicycle and Pedestrian Data Collection Manual, developed by University of Minnesota researchers and SRF Consulting Group, provides guidance and methods for collecting bicycle and pedestrian traffic data in Minnesota. The manual is an introductory guide to nonmotorized traffic monitoring designed to help local jurisdictions, nonprofit organizations, and consultants design their own programs.Bicycle and Pedestrian Data Collection Manual

Topics covered in the manual include general traffic-monitoring principles, bicycle and pedestrian data collection sensors, how to perform counts using several types of technologies, data management and analysis, and next steps for nonmotorized traffic monitoring in Minnesota. Several case studies illustrate how bicycle and pedestrian traffic data can be used to support transportation planning and engineering.

The manual was completed as part of the third in a series of MnDOT-funded projects related to the Minnesota Bicycle and Pedestrian Counting Initiative, a collaborative effort launched by MnDOT in 2011 to encourage nonmotorized traffic monitoring across the state. U of M researchers, led by professor Greg Lindsey at the Humphrey School of Public Affairs, have been key partners in the initiative since its inception.

In addition to the manual, U of M researchers have published a final report outlining their work with MnDOT on this project. Key accomplishments include:

  • A new statewide bicycle and pedestrian traffic-monitoring network with 25 permanent monitoring locations
  • A district-based portable counting equipment loan program to support MnDOT districts and local jurisdictions interested in nonmotorized traffic monitoring
  • Minnesota’s first Bicycle and Pedestrian Annual Traffic Monitoring Report
  • A MnDOT website for reporting annual and short-duration counts that allows local planners and engineers to download data for analysis
  • Provisions added to MnDOT equipment vendor agreements that enable local governments to purchase bicycle and monitoring equipment
  • Annual training programs for bicycle and pedestrian monitoring
  • Provisions in the Statewide Bicycle System Plan and Minnesota Walks that call for bicycle and pedestrian traffic monitoring and creation of performance measures based on counts

“This is an excellent resource that steps through all aspects of managing a count program, and I think it will be very helpful to other states and organizations that want to implement their own programs,” says Lisa Austin, MnDOT bicycle and pedestrian planning coordinator. “Since Minnesota is a leader in counting bicycle and pedestrian traffic, it also fulfills what I think is an obligation to share our story with others.”

Work-zone warnings could soon be delivered to your smartphone

Imagine that you’re driving to work as usual when your smartphone announces, “Caution, you are approaching an active work zone.” You slow down and soon spot orange barrels and highway workers on the road shoulder. Thanks to a new app being developed by University of Minnesota researchers, this scenario is on its way to becoming reality.

“Drivers often rely on signs along the roadway to be cautious and slow down as they approach a work zone. However, most work-zone crashes are caused by drivers not paying attention,” says Chen-Fu Liao, senior systems engineer at the U’s Minnesota Traffic Observatory. “That’s why we are working to design and test an in-vehicle work-zone alert system that announces additional messages through the driver’s smartphone or the vehicle’s infotainment system.”

As part of the project, sponsored by MnDOT, Liao and his team investigated the use of inexpensive Bluetooth low-energy (BLE) tags to provide in-vehicle warning messages. The BLE tags were programmed to trigger spoken messages in smartphones within range of the tags, which were placed on construction barrels or lampposts ahead of a work zone.

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The researchers also developed two applications for the project. First, they designed a smartphone app to trigger the audio-visual messages in vehicle-mounted smartphones entering the range of the BLE work-zone tags. A second app allows work-zone contractors to update messages associated with the BLE tags remotely, in real time, to provide information on current conditions such as workers on site, changes in traffic, or hazards in the environment.

Field tests proved the system works. “We found that while traveling at 70 miles per hour, our app is able to successfully detect a long-range BLE tag placed more than 400 feet away on a traffic barrel on the roadway shoulder,” Liao says. “We also confirmed the system works under a variety of conditions, including heavy traffic and inclement weather.”

“This was a proof of concept that showed that smartphones can receive Bluetooth signals at highway speeds and deliver messages to drivers,” says Ken Johnson, work-zone, pavement marking, and traffic devices engineer at MnDOT. “Future research will look into how we should implement and maintain a driver alert system.”

This future work includes using the results of a human factors study currently under way at the U’s HumanFIRST Laboratory to create recommendations for the in-vehicle message phrasing and structure. Then, researchers plan to conduct a pilot implementation with multiple participants to further evaluate the system’s effectiveness.

According to MnDOT, another phase of the project may investigate how to effectively maintain the BLE tag database. This phase could also investigate implementation options, such as how MnDOT can encourage drivers to download and use the app.

Taconite byproduct reduces road wear from studded tires

In a recent project, the Alaska Department of Transportation (DOT) used a byproduct of Minnesota’s taconite mining industry for a section of the Alaska Glenn Highway.

The taconite byproduct—Mesabi sand—serves as the aggregate of a sand-seal treatment for a 4,600-foot stretch of the highway just north of Anchorage. Sand seals are an application of a sealer, usually an emulsion, immediately followed by a light covering of a fine aggregate (the sand).

“Our goal was to explore pavement preservation measures that extend pavement life and that also resist studded tire wear,” says Newton Bingham, central region materials engineer with the Alaska DOT. “Studded tires are allowed from mid-September until mid-April, and they cause rapid pavement wear.”

For the project, the Alaska DOT obtained sample pavement cores from the test area in 2014. Researchers then applied sand seals with two different hard aggregates—calcined bauxite and the Mesabi sand—to the surface of the cores to evaluate the effectiveness of each treatment.

Larry Zanko, senior research program manager of the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth, was the on-site representative for the taconite sand analysis. NRRI focuses on strategies to recover and utilize mineral-resource-based byproducts such as taconite and find potential beneficial end-uses for them.

“Taconite is one of the hardest natural aggregates,” he says. “Minnesota’s taconite mining industry generates tens of millions of tons of byproduct materials every year that could be used as pavement aggregate. Friction aggregates could be a higher-value niche for the industry.”

Testing of the sand-seals showed similar wear resistance for both types of aggregates. “We chose taconite sand since it is available from Minnesota as an industrial byproduct, whereas calcined bauxite sand has to be imported from nations on the Pacific Rim and costs more due to shipping,” Bingham says.

The Alaska DOT reports good performance to date on Glenn Highway and is funding ongoing pavement wear measurement.

NRRI researchers are also studying the use of taconite for other pavement applications. Funded by MnDOT, Zanko’s team developed (and later patented) a taconite compound for repairing pavement cracks and patching potholes (see an article the September 2016 Catalyst). The long-lasting patches reduce maintenance costs and traffic disruption. In continuing work funded by the Minnesota Local Road Research Board, researchers will refine the repair compound and develop and field-test a low-cost mechanized system for pavement and pothole repairs.

Videos trace progress in traffic operations, pavement design

Last month, CTS debuted two videos about the many contributions U of M researchers have made—and are still making—in traffic operations and pavement design.

The videos are one of the ways CTS is marking 30 years of transportation innovation. Our goal is to show how research progresses over time—from curiosity to discovery to innovation. The videos also show how U of M research meets the practical needs of Minnesotans in the Twin Cities metro and throughout the state.

The first video focuses on improving traffic operations, a research focus since our earliest days. Professor Emeritus Panos Michalopoulos invented Autoscope® technology to help transportation agencies capture video images of traffic and analyze the information, enabling better traffic management. Autoscope was commercialized in 1991, and the technology has been incorporated into products sold and used worldwide.

Current traffic operations research builds on this strong foundation. For example, the U’s Minnesota Traffic Observatory, directed by John Hourdos, develops data collection tools such as the Beholder camera system. The system is deployed on high-rise rooftops overlooking a stretch of I-94 in Minneapolis—an area with the highest crash frequency in Minnesota—to help the Minnesota Department of Transportation reduce congestion and improve safety.

The second video showcases U of M research on pavement design. Developing pavements that can stand up to Minnesota’s harsh climate is a continuing priority for researchers, whose work has led to new methods, tools, and specifications to extend pavement life. The video also looks at how research teams are pushing the envelope with use of materials such as taconite waste and graphene nano-platelets for pavement applications.