Environment, Research

A look at five great environmental research projects

1 Comment

To mark Earth Day 2016, MnDOT Research Services is taking a glance at five stellar examples of current research projects at MnDOT that involve pollution control, wetland mitigation, road salt reduction and new ways of recycling pavement.

1: Reducing Road Construction Pollution by Skimming Stormwater Ponds 

Temporary stormwater ponds with floating head skimmers can remove clean water from the surface of a settling pond.

Soil carried away in stormwater runoff from road construction sites can pollute lakes and rivers.

Stormwater settling ponds provide a place for this sediment to settle before the water is discharged into local bodies of water. However, since stormwater ponds have limited space, a mechanism is needed to remove clean water from the pond to prevent the overflow of sediment-laden water.

MnDOT-funded researchers designed temporary stormwater ponds with floating head skimmers that can remove clean water from the surface of the settling pond, using gravity to discharge water into a ditch or receiving body.

The study, which was completed in spring 2014, identified five methods for “skimming” stormwater ponds that can improve a pond’s effectiveness by 10 percent. MnDOT researchers also created designs for temporary stormwater ponds on construction sites with the capacity to remove approximately 80 percent of suspended solids.

These designs will help contractors meet federal requirements for stormwater pond dewatering. Researchers also determined how often a pond’s deadpool must be cleaned, based on watershed size and pool dimensions.

2: Roadside Drainage Ditches Reduce Pollution More Than Previously Thought  

Photo of roadside ditch
Stormwater infiltration rates at five swales were significantly better than expected based on published rates.

Stormwater can pick up chemicals and sediments that pollute rivers and streams. Roadside drainage ditches, also known as swales, lessen this effect by absorbing water. But until recently, MnDOT didn’t know how to quantify this effect and incorporate it into pollution control mitigation measures.

In a study completed in fall 2014, researchers evaluated five Minnesota swales, measuring how well water flows through soil at up to 20 locations within each swale.

A key finding: grassed swales are significantly better at absorbing water than expected, which may reduce the need for other, more expensive stormwater management practices, such as ponds or infiltration basins.

This could save MnDOT and counties significant right-of-way and construction costs currently expended on more expensive stormwater management techniques.

3: Could Permeable Pavements Eliminate Road Salt Use on Local Roads? 

Robbinsdale
Even with little or no road salt, a permeable pavement like this porous asphalt in Robbinsdale, Minnesota, collects little slush and snow in the winter because it warms well and remains porous enough to infiltrate surface water effectively.

Road salt is used for de-icing roadways during winter months, but can have a negative impact on the environment.

This research, which was just approved for funding through the Minnesota Local Road Research Board in December 2015, will investigate the reduction in road salt application during winter months that can be attained with permeable pavements, while still providing for acceptable road safety.

Some initial investigations (see previous study) suggest that road salt application can be substantially reduced, even eliminated, with permeable pavement systems. The proposed research will investigate this hypothesis more thoroughly, and further document the reduction in road salt application that can be expected with permeable pavement.

4: Highway 53 Shows Potential of Using Road Construction Excavation Areas For Wetland Mitigation

IMG_2764
This photo from spring 2015 shows that wetlands have begun to take hold along Highway 53.

Road construction in northeast Minnesota often causes wetland impacts that require expensive mitigation. However, borrow areas excavated for road construction material can be developed into wetland mitigation sites if hydric vegetation, hydric soils and adequate hydrology are provided. Fourteen wetland mitigation sites were constructed north of Virginia, Minnesota along the U.S. Trunk Highway 53 reconstruction project corridor and evaluated for wetland.  The sites were established with the goal of mitigating for project impacts to seasonally flooded basin, fresh meadow, shallow marsh, shrub swamp, wooded swamp, and bog wetlands. All but one of the sites consistently meet wetland hydrology criteria.

The sites contain a variety of plant communities dominated by wet meadow, sedge meadow, and shallow marsh. Floristic Quality Assessment (FQA) condition categories for the sites range from “Poor” to “Exceptional.”

According to the research report published in March 2016, these sites have shown the potential for creating mitigation wetlands in abandoned borrow pits in conjunction with highway construction. Adaptive management, particularly water level regulation, early invasive species control, tree planting, and continued long-term annual monitoring can make mitigation sites like these successful options for wetland mitigation credit.

5: Recycling Method Could Give Third Lives to Old Concrete Roads 

2016-14 Image
This photo shows a cold in-place recycling equipment train in action.

MnDOT already extends the lives of some old concrete highways by paving over them with asphalt instead of tearing them up. Now MnDOT hopes to add a third life for these old concrete roads by using a process called cold in-place recycling to re-use that existing asphalt pavement when it reaches the end of its life.

Cold in-place recycling (CIR) uses existing pavements, without heat, to create a new layer of pavement. It involves the same process of cold- central plant mix recycling (which is being employed by MnDOT for the first time on two shoulder repair projects this year), but it is done on the road itself by a train of equipment. It literally recycles an old road while making a new road.

CIR has been in use in Minnesota for 20 years, but only with hot-mix asphalt (HMA) over gravel roads. The purpose of a new study, which was approved for funding in April 2016, is to validate Iowa’s promising new practice using CIR on bituminous over concrete.

In this research project (see proposal), MnDOT will use cold-in-place recycling to replace the asphalt pavement on a concrete road and then evaluate it for several years, comparing it also with control sections.

Along with the potential of a better service life, the cost of CIR is much lower than new hot mix asphalt (HMA). Therefore, a 20-percent to 30-percent price reduction per project may be realized.

Maintenance Operations

Driver-assist system helps keep plows on the road

Leave a comment
Darryl Oeltjenbruns, snowplow driver in District 7, operates the only driver assist system, or DAS, equipped snowplow in the state. The system helps snowplow operators see road alignments and features such as turn lanes, guardrails and road markings. (Photo by Chase Fester)
Darryl Oeltjenbruns, snowplow driver in District 7, operates the only driver assist system, or DAS, equipped snowplow in the state. The system helps snowplow operators see road alignments and features such as turn lanes, guardrails and road markings. (Photo by Chase Fester)

By Sue Roe, MnDOT Communications

Southwest Minnesota has the highest average wind speeds in the state—bad news for MnDOT snowplow operators who often drive in low visibility to clear roads.

“We have more days when the wind blows than when it doesn’t,” said Chase Fester, MnDOT District 7 transportation operations supervisor. “We struggle with the wind.”

That’s why District 7 is piloting a snowplow driver-assist system (DAS) developed by University of Minnesota researchers to combat the blowing snow and fog that often cause zero visibility. The DAS helps snowplow operators see the road alignment and features, such as turn lanes, guardrails, and road markings. Even in less extreme winter weather, snowplow operators gain assurance of their lane location using the system.

The driver assist system displays a white box on the screen when an obstacle, or in this case a mailbox, is located. If the object appears in the lane, such as a car stuck in a snow drift, the box turns red and gets bigger as the snowplow gets closer to the object. (Photo courtesy of MnDOT District 7)
The driver assist system displays a white box on the screen when an obstacle, or in this case a mailbox, is located. If the object appears in the lane, such as a car stuck in a snow drift, the box turns red and gets bigger as the snowplow gets closer to the object. (Photo courtesy of MnDOT District 7)

The DAS was developed and refined over the past 20 years under multiple research projects funded by MnDOT and the USDOT’s University Transportation Center program. Professor Max Donath, director of the University of Minnesota’s Roadway Safety Institute, led the work. In addition to plows, the DAS technology has also been applied in other specialty vehicles such as patrol cars and ambulances. Numerous vehicles using the system have been deployed in both Minnesota and Alaska.

The DAS uses GPS technology and a front-mounted radar to provide an image of the road and any obstacles in front of the operator. The image is displayed on a monitor inside the cab of the plow. The system also vibrates the operator’s seat as a warning if the plow veers too close to the roadway’s centerline or fog line.

“If the driver gets within one foot of the fog line on the right side, the right side of the seat vibrates. If the driver gets too close to the centerline on the left side, the left side vibrates,” said Fester.

The vibrations continue until the driver moves back into the center of the lane. The driver can also turn off the warning feature to clear snow from the shoulder.

The DAS is currently installed in one truck in District 7. The $75,000 cost makes it difficult to install in every truck in the district or the state, although having at least one system in every district may be possible, Fester said.

Fester said the system proved its worth one day in February when blizzard conditions caused zero visibility and forced many road closures in southwest Minnesota. He was called out at 2 a.m. Feb. 8 to assist a stranded state trooper and several motorists on a 12-mile stretch of Hwy 60 between Windom and Heron Lake. Fester drove a pickup behind the DAS-equipped snowplow, driven by Darryl Oeltjenbruns, to reach them.

As the DAS identified stranded vehicles on the way to Heron Lake, Fester and Oeltjenbruns checked to make sure they weren’t occupied with people. Once they made it to Heron Lake, they stopped at the community center, where the state trooper and the stranded motorists he brought in were located.

On the way back to Windom, Fester and the state patrolman continued to check on stranded vehicles as the DAS-equipped snowplow led the way. If the vehicles weren’t in the ditch, motorists drove behind the two MnDOT vehicles. If their vehicles were in the ditch, motorists rode in a Suburban that was also being escorted to Windom. After returning to Windom, the motorists were dropped off at motels or truck stops.

“When we first went out, there were about six stranded vehicles. Coming back from Heron Lake, there were about 15,” Fester said. “At one time, we had 12 vehicles in line as we drove back to Windom, driving about 10 to 15 miles per hour.”

Later that morning the DAS system was used again to locate other motorists.

“We continued to use it until about 10 a.m. or 11 a.m. that day,” Fester said. “The system worked great and kept everyone safe. It was an interesting morning.”

(Reprinted and adapted with permission from an article by Sue Roe in MnDOT’s Feb. 17, 2016 Newsline.)

Rail, Research, Trucking

‘New logistics’ will change the way goods are delivered—and how the road network is used

Leave a comment

Today, moving freight accounts for more than a third of the world’s transport energy—and that share is growing. The rise in global trade, online retailing, and business-to-business delivery is not only changing how goods are moved but also the type of goods moved and how far or frequently they are transported.

Currently, this massive movement of goods throughout the economy relies on an intricate—and largely decentralized—multimodal network of truck, rail, ship, and airplane delivery. However, change is on the horizon. In a study sponsored by MnDOT and the Minnesota Local Road Research Board, U of M experts outline the important impacts these changes will have on the road network and transportation infrastructure.

“There is hope that new methods of organization and proposed standardization will increase efficiency of freight movement and give rise to a new era of goods transport,” says Adam Boies, an assistant professor in the Department of Civil, Environmental, and Geo- Engineering (CEGE). “In the years to come, we expect that advances in logistics systems will be enabled by new technologies, approaches, and the desire for increased efficiency.”newlogistics2

Changes in the way logistics operations are organized will help drive advances. New information technology permits the sharing of data between and across businesses, which in turn drives efficiency and leads to fuller vehicles. “This may reduce the distance traveled by heavy goods vehicles per unit of GDP, which may in turn reduce costs and entice more demand for delivered goods,” says CEGE professor David Levinson, the study’s principal investigator. “Ultimately, this could mean fewer trips by individual consumers and more deliveries. We anticipate the result will be a net reduction in distance traveled.”

The study also examined some of the potential drivers for changes in the freight industry as a result of logistics reorganization. These include supply chain pooling, in which individual logistics operations are shared between collaborators, and the Physical Internet Initiative, which seeks to create standards for packaging to enable the homogenization of freight technology. “While both of these advancements have the potential to increase logistics efficiency by reducing the transportation of empty loads, they will also increase truck weights—which may increase pavement damage,” Boies says.

Other transportation and logistics changes will result from shifts in the ways businesses and consumers receive goods and services, including business-to-business systems and technologies that enable a sharing economy, same-day delivery services, 3-D printing, and “last mile” delivery services. In addition, a growing portion of purchases can be delivered directly over the Internet. “Delivery is easily automated for data-based goods like books, music, video, and software,” Levinson says. “Purchases that could once only be completed by moving things can now be done by moving data.”

The research is part of a multi-pronged study that analyzed the technological shifts altering surface transportation and the implications for Minnesota. Findings are available in a final report: The Transportation Futures Project: Planning for Technology Change.

Maintenance Operations, Research

Willow shrubs could be next great Minnesota snow fence

1 Comment

The benefits of living snow fences and other snow control tools to keep roadways clear of blowing and drifting snow have been known for decades, and MnDOT has been using a variety of these techniques for years to catch  snow before it gets to a road.

Living snow fences often consist of trees, grasses and even corn stalks left standing in a farmer’s field.  Now willow shrubs are being added to the list as a fast-growing, inexpensive snow control measure.

What’s new

WillowSeptember
Fish Creek willow shrubs (left) grow alongside corn in September 2015.

Researchers recently completed a study that investigated whether willow shrubs could make good living snow fences. While typical snow-fence plants, such as dogwood or cranberry shrubs, can take five to 20 years to establish themselves, shrub willows were effective at trapping snow after just two growing seasons, according to the study.

In spring 2013, researchers installed three varieties of shrub willow side-by-side in two-row and four-row configurations along about a quarter of a mile of Highway 14 in Waseca, where snow drifts are an issue. In April 2014, they cut the shrubs down to the ground  to encourage branching and bush density. Though the trimmed willows had little impact on drifting snow the first winter, each willow-shrub plot was collecting two to three metric tons of snow by the second winter, according to the research report. Researchers believe that after three or four growing seasons the willow shrubs could catch the entire mean annual snowfall on the site.

In the four-row configuration recommended by researchers, costs of raising, furnishing, planting and mulching came to about $3.60 per plant, which is dramatically less than the contract bid cost for traditional living snow fence species that cost more than $50 per plant. In addition, the willow shrubs could be harvested and sold as biomass every few years to provide an income source.

Past research

Willow trees is just the latest advancement in the state’s snow control program. A 2012 research project evaluated the costs and benefits of living snow fences and provided MnDOT with a payment calculator to determine how much to compensate landowners for installation and maintenance costs.

A recent research implementation project created a mobile-friendly Web version of the payment calculator tool.  The website also contains a tool for designing a own snow fence.

MnDOT has used these tools and other promotional efforts to nearly double the number of farmers with contracts for corn rows enrolled in the Living Snow Fences program.

What’s next

The willow species recommended by researchers will be evaluated further in 2017 when they install it as a living snow fence on a new construction site on Highway 60 between Windom and Mountain Lake. Researchers also recommend a future study to compare volume of road salt use before and after installation. They also want to look into identifying appropriate buffer distances to keep willow roots from interfering with cropland root systems.

Resources

Research

Alternative fuels will help shape Minnesota’s transportation future

2 Comments

The mix of fuels used to power the vehicles on our nation’s roadways is diversifying rapidly.  While gasoline and diesel are still dominant, an increasing percentage of vehicle power is coming from alternatives such as biofuel, natural gas, and electricity. What could this shift mean for Minnesota’s transportation future? MnDOT and the Minnesota Local Road Research Board turned to U of M experts for analysis.

“The rise of alternative fuels is something we need to keep a close eye on, because it presents a number of issues that may significantly alter our state’s transportation system,” says Adam Boies, an assistant professor in the U of M’s Department of Civil, Environmental, and Geo- Engineering (CEGE).

Minnesota leads the nation in biofuel use, in part due to a series of legislative acts designed to encourage ethanol production and consumption. Boies predicts, however, that biofuel consumption in the state is near saturation and that future shifts will likely be between biofuels. “These shifts may alter the routes of heavy-goods vehicles in the state as refineries shift from corn and soy to fuels derived from agriculture wastes and forest byproducts,” he says.

If the price of natural gas remains significantly lower than diesel fuel, natural gas vehicles will likely make up an increasing share of the heavy-duty vehicle fleet in Minnesota. A larger natural gas refueling infrastructure will need to be developed, most likely by private organizations that manage fleets of vehicles. “As this happens,” Boies says, “efforts must ensure that natural gas vehicles and refueling infrastructure do not emit significant quantities of methane, which has a high global warming potential.”

Minnesota electric vehicle sales have lagged behind the nation—winter temperatures are one factor—but Boies expects the numbers to rise. He estimates 16 percent of new cars sold in Minnesota in 2035, and 56 percent in 2050, will be electrified. The growing numbers will require a more robust charging infrastructure, likely supplied or subsidized by government agencies, he says.

In the long term, on-road charging systems are being investigated. In these systems, under study in several countries, charging coils embedded within the roadway transfer power wirelessly to vehicles. “The systems could make electric vehicles drastically more efficient by reducing vehicle battery size,” he says.

Better vehicle efficiency is likely to continue the trend of falling fuel tax revenues. “Minnesota will need a method for producing revenues from electric vehicles to maintain long-term funding for the transportation road network,” he says. “Currently the higher price of electric vehicles results in increased revenues during vehicle registration, which tends to offset the difference in fuel tax revenues. However, as the price differential between electric vehicles and traditional vehicles shrinks, there will be decreased funding for Minnesota roadways unless additional revenue sources are found.”

Finally, emphasis on fuel efficiency in the light-duty and heavy-duty vehicle fleets will drive the weight of these vehicle segments in opposite directions. “Light-duty vehicles will get lighter and heavy-duty vehicle fleet operators will lobby for increased weight limits on Minnesota roadways to reduce the energy intensity of goods deliveries,” Boies says. “This growing disparity in weight between the two vehicle classes may require increased safety measures to reduce the severity of crashes between vehicle classes.”

“The question of how alternative fuels and electric vehicles will impact the transportation system, ownership models, and operating costs, as well as vehicle and driver safety, are extremely important topics to study,” says Ken Buckeye, MnDOT program manager. “The potential for these trends to impact our revenue streams is also very significant. When you couple those trends with the federal mandate for a CAFÉ standard of 56 mpg by 2025, we are likely to see some profound impacts that reach across modes, jurisdictions, and funding mechanisms.”

Boies’s research is part of a multi-pronged study funded by MnDOT and the LRRB that analyzed the technological shifts altering surface transportation and the implications for Minnesota. Other contributors included CEGE professor and principal investigator David Levinson and associate professors Jason Cao and Yingling Fan of the Humphrey School of Public Affairs. Their high-level white papers are compiled in a final report: The Transportation Futures Project: Planning for Technology Change.

Research

MnDOT, LRRB select new research projects with eye toward results

Leave a comment

MnDOT’s latest crop of transportation research projects have been identified. This year, researchers were asked to pay special attention to how their work could benefit the public and be put into real-world practice.

MnDOT’s Transportation Research Innovation Group (TRIG) and the Minnesota Local Road Research Board recently announced their Fiscal Year 2017 funding awards after hearing proposals from researchers at multiple universities. The two bodies chose 20 research proposals totaling about $2.9 million that will study new and innovative approaches to improving the environment, making transportation systems safer, improving construction methods and operating in more cost-effective ways.

According to MnDOT Research Management Engineer Hafiz Munir, MnDOT Research Services made some key changes to its annual requests for proposal that will help ensure research makes a difference to the agency’s bottom line. This year, researchers were asked early on in the proposal process how they would quantify their results, what benefits the research could achieve and how their research could be implemented in the future.

“Now we’ll be able to track those metrics and that will help MnDOT not only quantify the potential benefits of the projects, but also implement the results,” Munir said. “The bottom line is that we will be able to not only save money, but also improve the way MnDOT does business.”

Several of the 20 newly funded projects deal with improving transportation safety, Munir said, and many others are focused on implementing cost-saving practices, innovations and new technologies.

The projects approved in December 2015 will do the following:

  • Create an inexpensive GPS-based system that alerts the driver when a motor vehicle deviates from a lane or approaches a curve. (Project summary)
  • Find out whether a smartphone app can effectively warn drivers about upcoming roadway curves. (Project summary)
  • Determine whether different types of roadway turfgrass are better suited for specific regions of the state. (Project summary)
  • Create a comprehensive design guide for fish-friendly culverts.  (Project summary)
  • Determine how social media can be used to engage diverse community groups within the state. (Project summary)
  • Investigate the performance of the state’s first glass fiber reinforced polymer (GFRP) reinforced bridge deck, slated for construction in 2016.  (Project summary)
  • Develop signage recommendations to slow high-speed traffic as it approaches roundabouts.  (Project summary)
  • Gather truck reliability data, identifying truck bottlenecks and providing potential mitigation solutions for regular congestion areas. (Project summary)
  • Determine why anchor bolts are becoming loose on overhead signs, light towers and other support structures — and how to prevent it.  (Project summary)
  • Establish a system and smartphone app for accurately capturing and reporting data about intrusions into work zones.  (Project summary)
  • Develop an advanced sensor system to estimate long-term and dynamic vertical displacements on the I-35W bridge. (Project summary)
  • Investigate the necessity of pavement markings on low-volume roads and develop an approach to prioritize pavement marking projects.  (Project summary)
  • Compare the performance of different structural fibers in thin concrete overlays.  (Project summary)
  • Evaluate four performance test methods that predict the cracking behavior of asphalt mixes. (Project summary)
  • Investigate the link between transportation investment and job creation, and analyze transportation investments, business patterns and socioeconomic data in Minnesota counties. (Project summary)
  • Refine a taconite-based pothole repair compound, and develop a low-cost mechanized system to mix and place it in large quantities.(Project summary)
  • Investigate how much road salting can be safely decreased with the use of permeable pavements. (Project summary)
  • Evaluate the use of iron-enhanced check dams for capturing phosphate and toxic materials from roadway runoff. (Project summary)
  • Improve accessibility calculation capabilities and understanding of travel behavior by integrating data about highway bus operations, park-and-ride facilities, and urban parking costs. (Project summary)
  • Investigate the concept of estimating traffic volumes from mobile device samples to collect traffic data inexpensively. (Project summary)

Munir said the next steps for these projects this spring include creating  technical advisory panels, finalizing project work plans and preparing contracts. Some projects could begin early, depending on available funding and project-readiness. By the time Fiscal Year 2017 begins on July 1, funding will be available to begin all 20 projects.

Maintenance Operations, Research

Taking the guesswork out of measuring winter operations

Leave a comment

Being able to accurately and reliably estimate traffic conditions during snow events is critical to transportation agencies. Typically, state DOTs use measurements such as “time to bare pavement”—based on the visual inspection of plow drivers—to gauge the progress of snow operations. These estimates are limited, however, by the subjectivity and inconsistency of human-based measurements.

Now, new research sponsored by the MnDOT and led by University of Minnesota Duluth civil engineering professor Eil Kwon aims to take the guesswork out of assessing traffic conditions during winter weather events.

“Dr. Kwon’s research on a new approach to snow and ice performance reporting is exciting,” says Steve Lund, state maintenance engineer and director of the Office of Maintenance at MnDOT. “For quite a few years, MnDOT snowfighters have been reporting their performance through a visual review of the roadway conditions. Our snowfighters have a tough job—automating the performance reporting will remove that task from their duties. Also, looking at traffic returning to a ‘normal’ condition is truly the ultimate goal or outcome measure, and where we want to go.”

In the first phase of this project, researchers developed a prototype process that uses data on traffic speed, flow, and density collected by loop detectors in the Twin Cities metro area to estimate the point at which traffic patterns return to normal—an indicator that the roadway surface has “recovered.” In the newly published second phase, researchers further analyzed the traffic flow patterns during snow events under normal and snow conditions and refined the earlier prototype into a traffic-data-based measurement process for snow operations.

“We found that by comparing the variation patterns in traffic flow during a snow event with those during normal weather conditions, we could successfully identify the recovery status of the traffic flow at a given location,” Kwon says.

Based on their findings, the researchers developed a new process to identify the Normal Condition Regain Time (NCRT)—as an alternative to the traditional “time to bare pavement” measurement used to gauge the progress of maintenance operations during a winter weather event.

One advantage of the new process is that it can reflect how road surface conditions affect traffic flow differently during day and night periods. “Nighttime traffic flow patterns are substantially different from those during daytime periods,” Kwon says. “We identified normal traffic patterns separately for daytime and nighttime conditions to account for these differences in estimating the recovery status.”

Future research plans include the development of an operational version of the NCRT estimation system that can be used on a daily basis to analyze and improve snow operations, and the creation of an online version that can be used for coordinating snow operations in real time.

“There is a lot of potential to use these findings to make snow operations even more effective and efficient,” Kwon says. “For example, the analysis of the relationship between the NCRT measures and operational strategies such as plowing start time and methods could help further refine MnDOT’s winter maintenance strategies.”

For more information, download the technical summary (PDF) or the project’s final report.

Maintenance Operations, Traffic and Safety

Video Demonstration: Robotic Message Painter Prototype

Video 2 Comments

In the above video, University of Minnesota-Duluth Associate Professor Ryan Rosandich tests a prototype of a robotic arm he developed to paint messages and markings on roadways. He calls the machine “The MnDOT Robot.”

During a test run in October 2015, the MnDOT robot painted a right-turn arrow and the word “ahead” on pavement at MnDOT’s Pike Lake station in Duluth.

Rosandich hopes commercial companies will show an interest in further developing his proof-of-concept technology into something that road authorities can use regularly to make work easier, faster and safer for their employees.

Companies interested in commercializing this technology can contact Andrew Morrow at amorrow@umn.edu.

Editor’s Note: The paint used in the above demonstration was diluted due to the cold weather at the time of the demonstration and does not reflect the condition of the paint expected in a typical application.

Education

Internship program helps students build skills, make connections

Leave a comment

While some interns spend their days making copies and coffee runs, Caitlin Johnson spent her summer internship working on a research project exploring ways to improve safety in work zones.

Johnson, a fifth-year civil engineering student, is one of eight undergrads from the University of Minnesota who participated in this year’s Summer Transportation Internship Program.

Interns worked at MnDOT for 10 weeks and gained valuable transportation-related experience in areas ranging from designing roadways to measuring pavement movement. The program, offered jointly by CTS and MnDOT, is now in its fourth year.

This year’s participants included the following students, working in these MnDOT offices:

  • Caitlin Johnson, Office of Traffic, Safety and Technology
  • Mamadou Mbengue, Office of Environmental Stewardship
  • Ellie Lee, Office of Design
  • Luke Horsager, Bridge & Hydraulics Office
  • Sheue Torng Lee, Materials & Pavement Office
  • Trenton Pray, Materials & Concrete Office
  • Colleen Tamara Maluda, Environmental & Vegetation Office
  • Lucas Karri, Bridge Office

Johnson says her internship at MnDOT gave her the opportunity to study a topic that hasn’t been explored in-depth in the past and present those findings to industry professionals, including staff from the Federal Highway Administration. Luke Horsager, a civil engineering senior, spent his internship with the Bridge & Hydraulics Office equipping MnDOT boats with new GPS and Bluetooth software used for river mapping and monitoring bridge scour. He says he enjoyed gaining hands-on experience with the technology.

Heidi Gray, a MnDOT Metro District designer who supervised intern Ellie Lee in the Office of Design, says the internship program is valuable not only for the students, but also for the supervisors and MnDOT as a whole. While the interns gained important hands-on work experience and made valuable professional connections, MnDOT supervisors were introduced to talented young professionals.

“It’s really good to get young people in here and teach them what MnDOT is all about,” Gray says. “I personally have enjoyed the opportunity to teach and pass along what I know. It’s a good refresher.”

Application materials for the 2016 Summer Transportation Internship Program will be available on the CTS website in early November.

For more information, read the full article in the September issue of Catalyst or visit the internship program web page.

Aviation, Bridges and Structures

Using drones to inspect bridges

1 Comment
MnDOT is researching how data and images collected by drones, such as the Aeryon Skyranger shown here, could aid bridge inspectors.
MnDOT is researching how data and images collected by drones, such as the Aeryon Skyranger shown here, could aid bridge inspectors.

In recent years, drones made headlines for fighting wars overseas, detecting crop conditions, keeping an eye on power lines and even delivering retail goods.

As the flying electronic devices became easier to use and less expensive, all sorts of individuals, businesses, nonprofit groups and government organizations – including the Minnesota Department of Transportation (MnDOT) – are exploring ways to use them.

This past summer, MnDOT began researching how to employ these unmanned aerial vehicles, or UAVs, to someday help inspect the state’s many bridges.

“That day may still be far off, but our initial project was an encouraging first step,” said Jennifer Zink, MnDOT bridge inspection engineer. “Phase 2 of the project will better provide details as to methods, criteria and cost effectiveness for how to apply drone technology best to bridge inspection.”

Project goal

Using drones could also minimize risks associated with current bridge inspection methods, which include rope systems and special inspection vehicles. (Photo by D.R. Gonzalez, MnDOT)
Using drones could help minimize risks associated with current bridge inspection methods, which include rope systems and special inspection vehicles. (Photo by D.R. Gonzalez, MnDOT)

The research team tested drones this past summer while inspecting four Minnesota bridges (in Chisago County, Olmsted County, Morrison County and near Stillwater) specifically selected for the study after an extensive evaluation and FAA approval.

Zink and her colleagues wanted to investigate whether drones could help MnDOT decrease the rising costs of bridge inspections and collect more detailed information. Drones could also minimize the risks for bridge inspectors, who currently use rope systems and special inspection vehicles to access hard-to-reach areas. Using a drone to gather images could keep inspectors out of harm’s way and inspection vehicles out of active traffic lanes.

“The goal of the project was to study the effectiveness and possibilities of using UAVs to aid in bridge inspection work, typically in gathering images without the use of an under-bridge inspection vehicle and in areas where access is difficult or not safe for an inspector,” Zink said. “There is no substantive guidance in existence for this application of this evolving technology. This initial effort was to gain a better understanding of potential capabilities, processes and planning best practices.”

FAA approval

Before simply launching drones and collecting bridge data, the research team reviewed current FAA rules and applied for the necessary exemptions. Approval was granted, but only for the use of an Aeryon Skyranger drone. Even though exemptions for several models were submitted to the FAA, none were approved in time for the field study.

The team, which included personnel from Collins Engineers Inc. and Unmanned Experts, also worked closely with the MnDOT Office of Aeronautics to plan the project and gain the necessary approvals. The Aeronautics Office recently published an official MnDOT drone policy.

In the air

Once in the air, the drone suitably performed a variety of inspection functions that didn’t require a hands-on physical inspection. Researchers tested the drone’s ability to gather high-quality still images and video footage of bridges. They also collected data from infrared cameras. In addition, the drone provided the ability to capture data needed to construct maps of bridge areas and 3D models of bridge elements.

“The images, including infrared images to detect deck trouble spots, obtained from the drone correlate to the findings in the bridge inspection reports for specific bridge elements,” Zink said.

Missing from the research were images of the underside of bridges. The drone model used in the study wasn’t able to shoot images upward from beneath a bridge, and inspectors identified that as a key feature along with the ability to operate without a GPS signal.

“The drone we used in this project was not completely ideal for an entire gathering of imagery for all bridge inspection elements as it was limited to GPS signal capability,” Zink said. “However, it did give us an idea of what a drone could provide, what the limitations were, and what features we would like to see on newly available UAV models. Unfortunately, our hands were tied with obtaining FAA exemptions only for the particular model used in this project within the funding timeframe.”

Conclusions and recommendations

The project’s final report listed several conclusions, including that drones can be used safely during bridge inspections and that risk to both the inspectors and public is minimal.

“Due to the successful outcome of the initial project, we have a better understanding of the drone capabilities we would like to use during an actual scheduled bridge inspection,” Zink said. “The drone that will be used in Phase 2 is specifically designed for inspection of structures. Several goals exist for the Phase 2 research project, and if we can accomplish them, they will decrease MnDOT’s costs and increase bridge inspection abilities. It could improve inspection data collection for local agencies as well.”

The researchers recently were notified that they received funding for Phase 2 of their project, which is expected to start later this fall.

Related links

Minnesota transportation research blog