Tag Archives: research

Seven Pilot Projects to Change Transportation Practice in Minnesota

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

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

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

Protecting the Environment and Wildlife

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

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

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

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

I-35W ‘Smart Bridge’ Test Site Uses Vibration Data to Detect Bridge Defects

By analyzing vibration data from the I-35W St. Anthony Falls Bridge, MnDOT is working to develop monitoring systems that could detect structural defects early on and ultimately allow engineers to improve bridge designs.

“With data spanning several years, the I-35W St. Anthony Falls Bridge offers a unique opportunity for investigating the environmental effects on a new concrete bridge in a location with weather extremes,” said Lauren Linderman, Assistant Professor, University of Minnesota Department of Civil, Environmental and Geo-Engineering. Linderman served as the research project’s principal investigator.

“This project gets MnDOT closer to using bridge monitoring systems in combination with visual inspection to help detect structural problems before they affect safety or require expensive repairs,” said Benjamin Jilk, Principal Engineer, MnDOT Bridge Office. Jilk served as the research project’s technical liaison.

2017-01-bridge.png
Completed in 2008, the I-35W St. Anthony Falls Bridge has a smart bridge monitoring system that includes hundreds of sensors.

What Was the Need?

In September 2008, the I-35W St. Anthony Falls Bridge was constructed to include a “smart bridge” electronic monitoring system. This system includes more than 500 sensors that continuously provide data on how the concrete structure bends and deforms in response to traffic loads, wind and temperature changes. Transportation agencies are increasingly interested in such systems. As a complement to regular inspections, they can help detect problems early on, before the problems require expensive repairs or lead to catastrophic failure. Smart bridge systems can also help engineers improve future bridge designs.

The smart bridge system on the I-35W St. Anthony Falls Bridge includes accelerometers, which provide data on the way the bridge vibrates in response to various stimuli, including structural damage. Vibration-based monitoring has the advantage of allowing damage to be detected at any location within the bridge rather than only at the specific locations where measuring devices have been placed.

However, it can be difficult to use vibration monitoring to detect damage when vibration is masked by the bridge’s natural response to traffic loads, wind, temperature changes and other environmental conditions. A crack in a bridge girder, for example, can produce a vibration signature similar to one produced by a change in beam length due to variations in temperature or other causes. Consequently, since 2008 MnDOT has conducted a series of projects using data from the St. Anthony Falls Bridge to establish a way to distinguish anomalous data indicating a structural defect or damage from background “noise” associated with other causes.

What Was Our Goal?

This project sought to develop a method for analyzing accelerometer data from the I-35W St. Anthony Falls Bridge that would show how the bridge naturally vibrates due to traffic, wind and other environmental conditions. With this fingerprint of the bridge’s natural vibration, engineers would have a baseline against which to measure anomalies in the data that might indicate structural damage.

What Did We Do?

A large amount of data has been collected from the bridge since its construction. To establish the vibratory fingerprint for the bridge, researchers examined the frequencies and shapes (or modes) of bridge vibration waves. The method they used to identify the data segments needed for the fingerprint was to evaluate the peak amplitude of bridge vibration waves and their root mean square (RMS), a measure of the intensity of free vibration.

The researchers applied this method to the vibration data collected on the I-35W St. Anthony Falls Bridge between April 2010 and July 2015, calculating the average frequencies for four wave modes and determining how they varied with the bridge’s temperature. They also calculated the way frequencies changed with the bridge’s thermal gradients, or variations in temperature between parts of the structure.

What Did We Learn?

The methods developed in this project were successful in establishing a fingerprint for the way the I-35W St. Anthony Falls Bridge vibrates due to environmental conditions, and a way to evaluate changes in vibration over time indicative of structural damage or other factors.

Researchers found that the ratio of peak signal amplitude to RMS in bridge vibrations was a strong indicator of data that should be analyzed, and was evidence of a large excitation followed by free vibration. By themselves, peak amplitude and RMS cannot distinguish between ambient free vibration and forced vibration.

Researchers were able to use this method to successfully analyze 29,333 data segments from the I-35W St. Anthony Falls Bridge. This analysis revealed that as temperature increases, the natural frequency of vibration tends to decrease. The magnitude of this change, they concluded, must be related not just to the elasticity of the bridge but also to other factors such as humidity. However, temperature gradients within the bridge did not appear to have a significant effect on the natural frequencies of the structure.

What’s Next?

MnDOT will continue to collect data from the bridge as it ages to further understand its behavior. This will provide an opportunity to determine how anomalies in vibration data correspond to cracking and other forms of structural distress. Ultimately, MnDOT hopes to use this bridge monitoring system in combination with visual inspection both to detect problems in bridges earlier and to develop better bridge designs. Researchers are also currently working on a follow-up project, Displacement Monitoring of I-35W Bridge with Current Vibration-Based System, to determine the effects of temperature on the bridge’s dynamic and long-term vertical displacements, which can be used to monitor the bridge’s stiffness, connections and foundations.

—-

This post pertains to Report 2017-01, Feasibility of Vibration-Based Long-Term Bridge Monitoring Using the I-35W St. Anthony Falls Bridge, published January 2017. 

Newly funded studies tackle big transportation questions

Can Twin Cities roadsides be used to grow habitat for endangered bumble bees? Are unseen factors affecting safety at rural intersectionsHow should Minnesota transportation agencies be preparing for connected vehicle technology?

Minnesota’s next round of transportation research projects will attempt to solve these and other questions facing the state’s transportation community. The Transportation Research and Investment Group, which governs MnDOT’s research program, and the Minnesota Local Road Research Board, which represents cities and counties, recently met and selected 21 transportation research projects for funding in fiscal year 2018.

A couple of MnDOT’s most interesting projects will evaluate the reuse of wastewater at safety rest areas and truck stations and develop a system to optimize the location of 80 truck stations due for replacement in the next 20 years. MnDOT will also partner with the Local Road Research Board to evaluate the use of personal warning sensors for road construction workers.

In addition to the problem of stripping underneath sealcoats on some city streets, other top research projects for local governments involve pedestrian safety enforcement and investigating whether rural, low-volume roads should be treated differently than urban roads for stormwater runoff. Current regulations govern runoff the same, regardless of daily vehicle count or surrounding land use.

“The selected research studies, which typically take one to three years to complete, will address some of the most major policy, environmental and maintenance dilemmas facing transportation practitioners,” said Linda Taylor, director of MnDOT Research Services & Library.

Below is a list of the selected projects, with links to associated need statements. Final project scopes will become available once contracts are approved. For further information, go here.

Bridges & Structures

Materials & Construction

Environmental

Planning

Maintenance Operations

Traffic & Safety 

MnDOT shares knowledge at national research conference

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.

trbThe 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.

img_1576
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

Thomas Burnham, Materials & Road Research

Kathryn Caskey, Transportation System Management

Shongtao Dai, Materials & Road Research

Dan Franta, District 7

Timothy Henkel, Modal Planning & Program Management 

Kyle Hoegh, Materials & Road Research

 Bruce Holdhusen, Transportation System Management

 Santiago Huerta, Metro District

Bernard Izevbekhai, Materials & Road Research

Brad Larsen, Metro District

Rita Lederle, Bridges

Francis Loetterle, Passenger Rail

Dean Mikulik, Materials & Road Research (student worker)

Mark Nelson, Transportation System Management

Steven Olson, Materials & Road Research

David Solsrud, Modal Planning & Program Management 

Trisha Stefanski, Modal Planning & Program Management 

Joel Ulring, State Aid for Local Transportation

Jennifer Wells, Bridges

Benjamin Worel, Materials & Road Research

Charles Zelle, Commissioner

Knowing While Mowing: GPS Keeps Maintenance Workers Out Of the Weeds

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.”

CTS Research Conference: a day of discovery and innovation

Have you registered to attend the annual CTS Transportation Research Conference on November 3?

The one-day event, held at The Commons Hotel on the U of M campus, will highlight new learning, emerging ideas, and the latest innovations in transportation. Sessions will also explore implementation efforts and engagement activities.

In the opening session, “Creating Sustainable, Livable, Forward-Compatible Cities for Economic Resilience,” author Gabe Klein will explore the innovations taking place in cities and how government, business, and nonprofit leaders can utilize this wave of change to shape a quality of life that is improved and not compromised.

Following his presentation, the following panel of experts will share perspectives on the implications for the future of transportation systems in Minnesota cities:

  • Mayor Ardell Brede, City of Rochester
  • Mayor Chris Coleman, City of St. Paul
  • Anu Ramaswami, Professor, Humphrey School of Public Affairs, University of Minnesota
  • Mayor Betsy Hodges, City of Minneapolis (invited)

In the luncheon presentation, “How to Promote and Prepare for Automated Driving,” Professor Byrant Walker Smith will present steps that governments can take now to encourage the development, deployment, and use of automated driving systems.

Complete program details and registration information is available on the CTS website. Please plan to join us for a day of discovery and innovation!

Drone Project Earns State Government Innovation Award

The MnDOT Office of Aeronautics and Aviation was recognized last month for the drone research project that also involved the Office of Bridge and Structures and MnDOT Research Services.

The Humphrey School of Public Affairs, in partnership with the Bush Foundation, presented a State Government Innovation Award to recognize great work and to encourage an environment that allows agencies to deliver better government services to Minnesotans through creativity, collaboration and efficiency.

The project, titled Unmanned Aircraft Systems (UAV) Bridge Inspection Demonstration Project, found that using drones for bridge inspections improves safety, lessens traffic disruption and reduces work time. For one type of bridge, inspection time shrank from eight days to five.

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.

More information

New video: Finding solutions to save lives

See how researchers at the Roadway Safety Institute (RSI), led by the University of Minnesota, are working to reduce crashes and save lives on our nation’s roadways in a new video.

The video features RSI director Max Donath and researchers from across the region who are working on a breadth of projects, ranging from reducing crashes at rail grade crossings to improving road safety on tribal lands. The video also highlights a few of RSI’s education efforts, including a museum exhibit designed to introduce preteens to safety concepts.

RSI was established as the Region 5 University Transportation Center in 2013 and is housed at CTS. MnDOT is a key partner for RSI, funding a variety of safety-focused projects by RSI researchers.

For more information about RSI, visit the Institute’s website.

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.