All posts by mndotresearch

Work Zone Safety- How to Make Construction Sites Safer

If you have spent any time driving on Minnesota roads and highways lately, you know that road construction work zones are all over the place. They can contribute to traffic delays and require vigilance to ensure the safety of both drivers and workers.

MnDOT and the Minnesota Local Road Research Board (LRRB) are doing their best to make  work zones more efficient and safer for crew members and the traveling public alike.

Here’s a roundup of some of the great work zone safety projects under way or recently completed:

New – Temporary Traffic Control for Low Volume Roads

FlyerPicCity and county workers sometimes have trouble determining how to select the appropriate work zone for low traffic roads. The Minnesota Local Road Research Board (LRRB) recently published two supplemental guidebooks to help local agencies identify the appropriate work zone layout for low-volume urban and rural roadways based on the maintenance activity. The guides are intended to supplement MnDOT’s 2014 Temporary Traffic Control Zone Layouts Field Manual.The LRRB has also requested changes to the field manual  for low-volume roadways in a letter to the MN Committee on Uniform Traffic Control Devices.

Smart Work Zone Speed Notification 

MnDOT is testing a system on I-94 this summer that it hopes will reduce work zone crashes by raising driver awareness of upcoming congestion. Systems with the same purpose have been tested in rural work zones, but mostly applied to locations where backups were predictable.

The Smart Work Zone Speed Notification System will take a different approach, informing drivers of the speed ahead, as opposed to a variable speed limit system tested previously on I-94, which also detected congestion but provided advisory speeds to drivers. It is envisioned that the new system will have greater success in reducing rear-end crashes on large, urban freeway work zones.

The new system is being tested and evaluated on I-94, east of downtown St. Paul, during work to replace and repair the roadway.

NEW –  Speed Cameras in Work Zones

OLYMPUS DIGITAL CAMERAPolice enforcement and speed limits are the main method of reducing the speed of drivers in Minnesota work zones. While this practice is effective, reducing speeds by approximately 10 to 15 mph, it is not practical to staff every work zone with law enforcement. As an alternative, some states are using automated speed enforcement cameras in work zones.

Automated speed enforcement cameras have been shown to reduce speeds in work zones, but such research did not evaluate how the cameras impact driver attention.

This study explored driver awareness and found that automated speed enforcement cameras in work zones are not a source of driver distraction. It also revealed differences in work zone driving behavior: Older drivers were least able to follow another vehicle closely, while younger drivers were least likely to monitor their speed carefully.

NEW –  Reducing Work Zone Delay by Improving Traffic Models

2016-12 ImageAccurate estimation of delays caused by lane closures on highways is critical important to effectively manage traffic flows around work zones.

A recent study, completed in March 2016, improves methods for estimating reduced traffic capacity and diversion rates for highway work zones.

Researchers analyzed traffic patterns from past work zones in the Twin Cities metro area and were able to develop a tool that can estimate estimate traffic diversion for a given work zone.

The next step is an implementation project to test and streamline the software.

Work Zone Intrusion Reporting

TRS1506 ImageWork zone intrusions — when traveling vehicles enter the work space of a work zone — are a clear safety concern even if they do not result in an accident, and they may indicate locations where future accidents are likely.

MnDOT was interested in learning how other state DOTs collect work zone intrusion data, both the technology used for data collection and the specific information they collect.

This Transportation Research Synthesis (TRS), completed in June 2015, surveyed state DOTs and conducted follow-up interviews with states that collect work zone intrusion data. The survey found that the relatively small number of states that do collect intrusion data typically do so via paper or electronic form.

As a result of the TRS, a recently funded research project proposes to develop a simple method to track and gather information on work zone intrusions. The aim of this process will be to produce a reporting interface (in the same vein as the Crash Report Usability And Design Project for the Department of Public Safety) that gathers essential information without being onerous to work crews.

Auto Flaggers: Keeping Crews Safe, Saving Manpower

Training was provided to introduce MnDOT maintenance workers to Automatic Flagger Assistance devices, which can improve safety in work zones by allowing flaggers to provide traffic guidance without having to be in the flow of traffic.

Using a remote control, a single worker can easily operate two AFADs simultaneously, freeing up personnel to perform other tasks and speed up the completion of a road project, the pilot study found. MnDOT estimates that the resulting cost savings can cover an AFAD’s purchase costs within two years.

MnDOT has planned a project to determine whether it is feasible to use a self-propelled device to push or pull an AFAD so it can be used in moving operations such as patching potholes or cracks, which make up more than half of MnDOT’s flagging operations.

Using Smartphone and Bluetooth Technologies to Help the Visually Impaired Navigate Work Zones 

2014-12 ImageIn a study released in February 2014, researchers developed and tested a new system to provide audible messages to visually impaired pedestrians for navigating work zones.

The system uses Bluetooth beacons attached to work zone infrastructure that sends messages to a pedestrian’s smartphone app rather than the traditional method of beeping buttons that announce a message when pressed.

Technology to Alert Drivers to Work Zones

2012-26 ImageBy creating a tactile vibration and sound, rumble strips effectively alert distracted drivers to potential danger. However, they are not suitable for moving operations because repositioning them is too labor-intensive. MnDOT needed a method of alerting drivers about upcoming work zones that is more dynamic than
static signs but is portable and can be used in a moving work zone.

The Intelligent Drum Line system, developed in a 2012, could significantly improve work zone safety by relaying audible and visual warnings from traffic drums to speeding drivers as they approach. Further development is needed to ensure the system is cost-effective and portable to serve MnDOT’s needs.

Protecting Bees & Butterflies With Right-of-Way

Bees, butterflies and other pollinators busily work on our behalf to help our crops and wild plant life reproduce. Most plants cannot produce fruits and seeds without the aid of these little bugs.

MnDOT is taking steps to ensure that the habitat these creatures depend on gets the protection it needs.

In addition to recently signing an agreement with five other state DOTs to improve pollinator habitat along Interstate 35, a key migratory corridor for Monarch butterflies, MnDOT has just completed a review of other state and local government practices to identify more opportunities to use existing right-of-way to protect pollinators.

“State roadways have acres and acres of habitat ideal for pollinators,” said MnDOT Commissioner Charlie Zelle, during the announcement about the I-35 initiative. “With some careful planning, we can ensure that Monarch butterflies and other creatures that pollinate are able to thrive, which ultimately benefits our food sources and us.”

New Opportunities for Protecting Pollinators

A Transportation Research Synthesis (TRS) released this week underscores MnDOT’s commitment to maintaining roadside habitat for pollinators.

MnDOT set out to learn about the experiences of other state departments of transportation and local agencies in maintaining pollinator landscapes on highway rights of way through partnerships with individuals, groups or local agencies.

Results of the literature review are supplemented with findings from a survey of selected state DOTs and Minnesota counties. Nine state DOTs describe current practices or plans to develop new pollinator-specific partnerships; existing partnerships that have been expanded to address pollinators; and Adopt-a-Highway programs that support maintenance of vegetation in the right of way.

The Transportation Research Synthesis (TRS) may lead to enhancements to MnDOT’s existing practices or the development of a new pollinator-specific partnership program.

While MnDOT does not have a community partnership that focuses solely on promoting pollinator habitat, its Community Roadside Landscape Partnership Program allows Minnesota communities to partner with MnDOT to establish and maintain landscaping in the ROW along highways that traverse their communities, and these landscaping treatments may benefit pollinators.

MnDOT has also partnered with the Minnesota Board of Water and Soil Resources and the Minnesota Department of Natural Resources to establish more than 20 native seed mixes for use on Minnesota roadsides. MnDOT’s online PlantSelector tool includes a seed mix tab to help designers and novices select the right seed for the right place.

Learn more:

Drones, slope slide prevention among MnDOT’s research implementation picks

Developing the guidance needed to begin using drones  for bridge inspections statewide is among the Minnesota Department of Transportation’s latest batch of research implementation projects.

MnDOT recently announced the selection of a dozen research implementation projects for funding in Fiscal Year 2017.  In addition to continuing MnDOT’s pioneering drone research, top initiatives aim to improve the accuracy of bridge load ratings and map slopes statewide to identify locations that are vulnerable to flash flooding.

Each winter, MnDOT solicits proposals from staff who want to put local or national research into practice in their day-to-day work.

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 best to integrate drones into its bridge inspection procedures.

The state research program’s governing board then selects projects for funding based on benefits, impacts on the department and support from management.

Project champions take previously proven concepts and help MnDOT turn them into useful practices and procedures to make the state’s transportation system better. Funds can be used for equipment, consultant services or researcher assistance.

“The research implementation program fills the gap between research and deployment of new methods, materials and equipment,” Bruce Holdhusen, MnDOT Research Services senior engineer, said.

Here are the 12 newly funded research implementation projects by category:

Bridge and Structures

  • Improving Quality of Bridge Inspections Using Unmanned Aircraft Systems (UAS)
  • Prestressed Concrete Beam Shear Rating
  • OmniScan Phased Array Ultrasonic Corrosion Imaging System

Environmental

  • MnDOT Slope Vulnerability Assessments

Maintenance Operations

  • Ultra-thin Bonded Wearing Course (UTBWC) Snow and Ice and Wind Effects

Materials and Construction

  • Cold In-Place Recycling (CIR) for Bituminous Over Concrete (BOC)
  • Geogrid Specification for Aggregate Base Reinforcement
  • Balanced Design of Asphalt Mixtures
  • Cone Penetration Testing (CPT) Design Manual for State Geotechnical Engineers

Policy and Planning

  • One-year Pilot Test and Evaluation of ASTM DOT Package Compass Portal

Traffic and Safety

  • Improve Traffic Volume Estimates from Regional Transportation Management Center (RTMC)
  • Understanding Pedestrian Travel Behavior and Safety in Rural Settings

The Future is Now: MnDOT Goes High-Tech

When it comes to creating the transportation system of the future, MnDOT is already doing its research and laying the groundwork for great things to come.

13-JamesBenhamTechnology300
James Benham, JB Knowledge, speaks at the Transportation Conference. (Photo by Rich Kemp)

Last month at Minnesota’s Transportation Conference, a keynote session by JB Knowledge CEO James Benham titled “Future Forecast: How Drones, Sensors, and Integrated Apps are Rewriting the Rules” inspired many people in the room.

Among the topics Benham cited in his talk were the Internet of Transportation, unmanned aerial vehicles (drones) and 3-D printing, which MnDOT is already studying or even using.

Internet of Transportation

MnDOT recently produced series of white papers on technological trends that could impact transportation infrastructure in Minnesota.

In January, MnDOT Research Services published these papers in a report titled “The Transportation Futures Project: Planning for Technology Change.”

GoogleCar
Google is one of many companies developing autonomous vehicle technology that researchers believe will make driving nearly extinct by 2040. (Photo courtesy of Google)

The report details how the transportation system can accommodate such imminent innovations as autonomous vehicles, mobile web services, mobility as a service, information and communication advances, infrastructure sensors and energy and fuel alternatives.

For example, researchers predict that driving faces near-extinction by 2040, when non-autonomous vehicles will no longer be allowed on public roads at most times. As a result, total transportation-related fatalities may drop 90 percent, road geometry, sightlines and other design priorities may shift, and capacity and speed limits will likely increase on most major roadways.

Unmanned Aerial Vehicles (Drones)

Drone
MnDOT is researching how data and images collected by drones could aid bridge inspectors.

When it comes to drones, MnDOT is already conducting important research that the rest of the nation is closely following. Tara Kalar and Jennifer Zink from MnDOT, and Barritt Lovelace of Collins Engineers, spoke about their efforts at last month’s conference.

Last year, MnDOT Research Services published a report titled “Unmanned Aerial Vehicle (UAV) Bridge Inspection Demonstration Project” that detailed how MnDOT could use drones to perform bridge inspection functions. The initial research project tested one drone’s capability in a variety of bridge inspection scenarios last summer at four Minnesota bridges.

In November, researchers conducted a second research phase to test a more specialized drone at the Blatnik Bridge in Duluth that coincided with that bridge’s regularly scheduled inspection.

A few weeks ago, researchers secured funding to conduct a research implementation project that aims “to implement a statewide UAS (unmanned aircraft systems) bridge inspection contract, which will identify overall cost effectiveness, improvements in quality and safety, and future funding sources for both state and local bridges,” according to the project proposal.

3-D Printing

Benham’s talk also addressed 3-D printing, which Chad Hanson, a District 6 project manager, has already used successfully.

Hanson spoke at the conference about his experience using 3-D printing to create a model of the Red Wing Bridge project that brought the project idea to life. According to Hanson, the model enhanced public engagement and informed preliminary design efforts for the bridge.

Chad Hanson photo
Chad Hanson, District 6 engineer, used 3-D-printing to create a model of the Red Wing Bridge that was used during the project’s public engagement events. (Photo by Mike Dougherty)

Partners, stakeholders and members of the public could see, touch and hold the 3-D printed models, which accentuated the project’s engagement process.

A look at five great environmental research projects

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.

Driver-assist system helps keep plows on the road

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.)

Willow shrubs could be next great Minnesota snow fence

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

MnDOT, LRRB select new research projects with eye toward results

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.

Video Demonstration: Robotic Message Painter Prototype

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.

Using drones to inspect bridges

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.

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