The Future of Mobility series collects the perspectives of top U researchers and other national experts. In 17 articles, the authors scan the horizon and reflect on critical transportation topics. Each article recommends action steps for public officials and policymakers.
The MnDOT Library recently got a request for a copy of Minnesota Standard Specifications for Highway Construction from 1938. It might seem obscure, but the request was easy to fulfill because a digitized version of the manual was readily available in the newly launched MnDOT Digital Library.
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.
MnDOT employees are sharing knowledge and displaying leadership in Washington this week by delivering presentations and conducting meetings at the nation’s preeminent transportation conference.
The Transportation Research Board (TRB) 96th Annual Meeting held Jan. 8-12 at the Walter E. Washington Convention Center in Washington, D.C., is expected to draw more than 12,000 transportation professionals from around the world. According to its website, the 2017 event scheduled more than 5,000 presentations in more than 800 sessions and workshops addressing topics of interest to policy makers, administrators, practitioners, researchers, and representatives of government, industry, and academic institutions. TRB’s 2017 annual meeting theme is “Transportation Innovation: Leading the Way in an Era of Rapid Change.”
“Every year when TRB holds its annual meeting, MnDOT’s strong presence at the event is a reminder of our state’s commitment to top-notch transportation research,” said Linda Taylor, director of MnDOT Research Services and Library.
Brad Larsen (left), MnPASS Policy and Planning Program Director, speaks with a conference attendee during a poster session this week at the Transportation Research Board Annual Meeting in Washington, D.C. Larsen was one of two dozen MnDOT employees invited to deliver presentations at the national transportation research event.
The following is a roundup of MnDOT employees who were invited to deliver presentations and participate in key committee meetings along with their presentation topics and committees (not all staff may have attended the conference; however, due to limited funding or availability):
Kenneth Buckeye, Financial Management
Ken Buckeye poses in front of a poster he presented at the TRB annual meeting this week.
As the first big snow and ice storms sweep through parts of Minnesota today, we’d like to remind you of some of our great winter weather research studies. Here’s a list of some of this winter-related research from MnDOT and the Local Road Research Board:
Living snow fences
Living snow fences are trees, shrubs, native grasses, wildflowers, or rows of corn crops located along roads or around communities and farmsteads. These living barriers trap snow as it blows across fields, piling it up before it reaches a road, waterway, farmstead or community. Through multiple research efforts, MnDOT continues to advance its practices for living snow fences. Willow plants, which are which are inexpensive and fast-growing, are a new form of snow fence. MnDOT has also developed a tool that allows the agency to better offer a competitive payment to farmers.
According to recent studies, researchers believe Minnesota could eliminate salt usage on low-volume local roads by switching to permeable pavements. Permeable pavements — pavements that allow water to seep through them — have been studied in some Minnesota cities, and a research project is currently underway to further investigate how much salt reduction can be expected.
MnDOT’s Metro District developed a way to automatically determine when to stop plowing a highway after a snow storm. The method involves measuring traffic flow to determine when road conditions have recovered. Current practice calls for maintenance workers to visually inspect traffic lanes. The automated technique could potentially be more accurate and save time and costs.
Minnesota winters are no joke, and Minnesotans still need to get wherever they’re going despite harsh snow and ice conditions. That’s why MnDOT is constantly researching new and improved versions of salt and other deicing chemicals to keep roads safe at the least amount of damage to lakes, rivers and groundwater.
A couple years ago, MnDOT snowplow operators in southwestern Minnesota invented an experimental plow that uses the wind to cast snow from the road without impeding traffic or the operator’s view. This winter, MnDOT intends to test multiple types of snowplow blades as part of a larger research project comparing types of deicers.
While a lot of research has been done on the plow itself, MnDOT hasn’t forgotten to invest in research to improve in-cabin snowplow technology as well. Some of the great technology recently developed to assist snowplow drivers, includes a driver assist application that a MnDOT plow driver used last winter to navigate a storm and rescue stranded motorists. The agency is also studying equipment factors that can cause fatigue in snowplow operators.
When the snow melts every spring, the damage salt does to roadside grass is obvious. That’s why researchers have spent years looking into developing and implementing salt-tolerant grasses on roadside settings. The result of this effort has been the introduction and use of salt-tolerant sod and seed mixtures that are made up primarily of fine fescue species. MnDOT is also studying how chlorides are transported within watersheds in order to better focus efforts to reduce deicer usage in areas where it will have the biggest environmental impact.
MnDOT has developed a test that can tell whether a contractor’s proposed asphalt mix will cause the road to crack in the winter. Building roads using better asphalt mixes leads to less cracking and fewer potholes. The test is expected to save the state about $2 million per year.
It’s not all about cars and trucks. Minnesotans still ride bikes and walk in the winter. That why MnDOT assembled a comprehensive review of existing practices and policies from other states, as well as a summary of valuable publications that could be referenced while developing a new policy.
MnDOT research led to the development of a Maintenance Decision Support System and related components provide real-time, route-specific information to snow plow drivers, as well as recommended salt application levels. These recommendations have reduced chemical usage while still achieving performance targets for snow and ice clearance.
As temperatures fall and days get shorter, MnDOT Metro District maintenance workers are wrapping up a season of mowing grass along roadsides and in medians that they hope will prove a little more efficient than in the past.
Thanks to a research project that installed GPS devices in tractor cabs, operators have a better sense of exactly which areas they need to mow and which areas should be left alone. Five Metro District tractors were tested in 2015. This year, more than 40 tractors were fitted with the automated vehicle location (AVL) technology, which includes a GPS antenna, an on-board central processing unit (CPU) and an in-cab screen with a user interface.
Trisha Stefanski, Metro District asset management engineer, expects one of the biggest benefits of the project to be a reduction in herbicide use. Maintenance crews use herbicide to control the spread of noxious weeds that sometimes get spread during mowing operations. Mapping exactly where noxious weeds are, and providing that information to operators on a real-time, in-cab screen and user interface helps them mow around those areas.
“We’re really hoping it will reduce the amount of herbicide that we’re putting on our roadways by 50 percent,” Stefanski said. “We’re not certain that will be the number, but that’s what we’re hoping for. We think just not mowing those areas will not spread as many noxious weeds and so we don’t have to apply as much herbicide.”
Metro District operators, such as Jesse Lopez, give the AVL technology rave reviews.
“Basically you can see what you shouldn’t mow and what you should mow. So, it makes it easy for me. It’s just like playing a game,” Lopez said. “This actually helps me to optimize what my job is. I know exactly where I’m at and where I’m going. I think everyone should use it – absolutely everybody who is in a mowing situation or a plowing situation.”
In addition, the AVL technology helps maintenance supervisors keep tabs on exactly where their operators are in real time. It also helps supervisors complete reports by automatically providing the geographic areas where mowing has been completed.
Stefanski says the project has gone really well, and she hopes collecting more data over another mowing season will show real savings on herbicide use. In the meantime, she is thinking of other ways AVL technology could be applied to maintenance operations.
“What I really like about the project is that we are taking something used in a lot snow plows and a lot of other technologies – cars, other things, maybe UPS uses them – and we’re putting it into maintenance operations,” Stefanski said. “Having it for mowing, we can also use it for smooth pavements. We can also use it for other things in mowing operations.”
In the video, Jennifer Zink, MnDOT state bridge inspection engineer, explains the project, along with Tara Kalar, MnDOT associate legal counsel; Cassandra Isackson, director of MnDOT Aeronautics; and Bruce Holdhusen, MnDOT Research program engineer.
The initial drone project drew significant media coverage and a lot of attention from other state departments of transportation from all over the country.
A second phase of the project was approved year and is currently underway. A third phase is already in the planning stages.
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.
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
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.
James Benham, JB Knowledge, speaks at the Transportation Conference. (Photo by Rich Kemp)
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.
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)
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, 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.
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.
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.
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.
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.
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.
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.