(Feature image courtesy Michael McCarthy, Center for Transportation Studies.)
Earlier this year, we wrote about the Minnesota Bicycle and Pedestrian Counting Initiative, a project that developed guidelines and protocols to help transportation planners accurately count non-motorized traffic. This groundbreaking research involved a diverse partnership of state and local officials, University of Minnesota faculty, and private and nonprofit organizations.
On Wednesday, April 23, the project team (photo above) was honored with an award from the Center for Transportation Studies. Team members accepted the CTS Research Partnership Award in a ceremony at the McNamara Alumni Center in Minneapolis. The award is given each year to projects that have resulted in “significant impacts on transportation” and that draw on “the strengths of their diverse partnerships” to achieve their results.
The video below, produced by CTS, explains the importance of the project. MnDOT is now in the process of implementing the research results by installing permanent counters and using portable counters in select locations around the state. MnDOT plans to use the information for a variety of purposes, including planning, safety analysis, investment planning and quality-of-life analysis.
A new technology that uses 3D-imaging sonar will enable MnDOT engineers to visualize the substructure of a bridge in a way they never have before.
Until now, MnDOT has relied on human divers and depth finders to identify problems beneath the water.
Divers are limited by what they can see and feel in murky waters, however, and depth finders can only look down, not around.
“With this new technology, we will be able to provide high resolution three-dimensional images of underwater areas, structures and objects to show what is occurring, regardless of water clarity,” said MnDOT Bridge Waterway Engineer Petra DeWall, who has received funding from MnDOT’s Transportation Research Innovation Group to purchase the equipment.
Video imagery from a sonar inspection of Minneapolis’ Third Avenue bridge is above.
Currently, MnDOT hires engineer divers to physically inspect about 500 bridges every five years. They look for cracked concrete, exposed reinforcement and other detrimental conditions.
Although divers can spot issues, they can’t always thoroughly assess the scope of a problem, such as the amount of sediment being washed out around a bridge pier, a problem called bridge scour.
It can also be difficult — or dangerous — for divers to venture down for an inspection.
This was the situation last winter with the Third Avenue Bridge in downtown Minneapolis, where the streambed has degraded around a bridge pier, causing erosion to the pier.
“The Third Avenue inspection was not totally detailed. We knew there was a void under the bridge, but it was very hard to visualize,” DeWall said.
Early ice build-up halted further inspection in November, so MnDOT asked 3D sonar scanner manufacturer Teledyne BlueView to scan the area as a demonstration of its equipment.
A video of the inspection is below:
Multiple holes were cut in the ice sheet to deploy the sonar, which provided an image of the bridge scour by emitting sound-waves that created a point cloud.
“It gives you a large data set of where the sound reaches and comes back to the equipment,” DeWall explained.
The 3D image provides a level of detail that will enable repair and construction contractors to make more accurate bids, saving MnDOT money on projects.
Although dive inspectors are also beginning to invest in this new technology, MnDOT wants its own equipment to perform quick assessments of troublesome spots without going through the lengthy contracting process.
The Federal Highway Administration is conducting a pooled fund study to see if the technology eliminates the need for dive inspectors all-together.
MnDOT also plans to use its 3D scanning sonar to inspect repair projects and assess bridge construction.
One of DeWall’s first goals is to take a scan of the Hastings bridge after construction is complete, which will provide a baseline scan that can be compared against future inspections. The old bridge has had problems with the loss of rocks at its piers. It is unclear if the rock just sinks or is washed away downstream. Monitoring will let MnDOT see what is happening over time.
“Inspection is just one part of it,” DeWall said of the sonar equipment. “The big interest in this project is coming from our construction folks.”
Post-Construction
Imagine building a new house and not being able to complete the final walk-through.
This is the situation that transportation departments face when they build a new bridge, due to the limitations of underwater inspections.
“With 3D technology, you can go back afterward and check to make sure things were done the way they were supposed to,” DeWall said.
DeWall wishes the state had the scanner many years ago when a bridge was built that required expensive correction.
A bridge construction crew left construction material behind under the water, which wasn’t discovered until the redirected water flow caused significant erosion to the bridge pier.
Divers picked up that something was going on during a routine inspection, but engineers still had to bring in depth finders to get a better look. Due to the water current, they were limited in how close they could get to the bridge pier, and turbulence crashed their boat against the pier, damaging the transducer.
Not only would this 3D technology have provided a more thorough assessment than the depth finder, it also could have captured the imagery from a safe distance away.
The new Roadway Safety Institute, a $10.4 million regional University Transportation Center (UTC) established in late 2013, will conduct a range of research, education, and technology transfer initiatives related to transportation safety. Led by the University of Minnesota, the two-year consortium will develop and implement user-centered safety solutions across multiple modes.
The Institute will be a focal point for safety-related work in the region, which includes Minnesota, Illinois, Indiana, Michigan, Ohio, and Wisconsin. Other consortium members are the University of Akron, University of Illinois at Urbana-Champaign, Southern Illinois University Edwardsville, and Western Michigan University.
Max Donath, professor of mechanical engineering at the U of M, serves as the new Institute’s director. In this month’s issue of the CTS newsletter, Catalyst, Donath shared his vision for theInstitute.
According to Donath, the Institute will focus on addressing regional traffic safety priorities, educating the public, and attracting more professionals to the safety workforce by connecting with students.
Research topics will focus on two key areas, Donath said: high-risk road users and traffic safety system approaches. The goal of this work is to prevent the crashes that lead to fatalities and injuries on the region’s roads.
One unique Institute effort will involve working with American Indian communities in the region to explore and address the unusually high number of motor vehicle crash fatalities on tribal lands. “Our research will work to better understand why this is happening and to develop more effective solutions,” Donath said.
This blog post by University of Minnesota Professor Greg Lindsey was originally posted on the CTS Conversations blog.
April 9 is national Bike to Work Day, a day to celebrate those who choose bicycling as their principal mode of transportation for commuting, and a time to encourage more people to consider this healthy, efficient transportation option. Minnesota has much to celebrate in terms of bicycle commuting. Bike-Walk Twin Cities and Transit for Livable Communities are wrapping up the National Non-Motorized Pilot Program, a federally funded program to demonstrate the potential to increase biking and walking through focused investment in infrastructure and other interventions. Bicycle commuting rates in Minneapolis have climbed to 4.5%, and Minneapolis now ranks 20th in the nation in bicycle commute share. This is a noteworthy achievement, especially considering our notorious winter weather. These achievements, along with others such as the success of Nice Ride, our pioneering bike share program, have contributed to Minneapolis being named America’s most bike-friendly city by Bicycling Magazine. Celebration of these achievements – which represent hard work by hundreds of individuals and thousands of commuters – certainly is warranted.
But we only need look across municipal boundaries to know we had better put more energy into encouraging bicycling than into celebration. Bicycle commute rates in St. Paul remain below 2% less than half the Minneapolis rate, and rates in most suburban, exurban, and rural communities remain even lower. And the story remains essentially the same for all types of bicycle trips. Jessi Schoner, a doctoral candidate in the Department of Civil Engineering, is analyzing non-motorized mode shares for all trips recorded the Metropolitan Council’s recent Travel Behavior Inventory. Her analyses show that bicycling remains an urban phenomenon, with the share of all trips taken by bicycling highest in Minneapolis, followed by St. Paul, and then suburban and outlying communities. Why is this so? Better infrastructure no doubt is part of the reason, but there likely are other reasons, including housing patterns, access to employment, socio-demographic factors, and culture. Additional research is needed.
But this leads to additional reasons to be optimistic this Bike to Work Day: the commitments made by the Minnesota Department of Transportation (MnDOT) to foster multi-modal transportation systems and the agency’s investments in research to increase understanding of bicycle traffic patterns. In 2013, as part of the Minnesota Bicycle and Pedestrian Counting Initiative, MnDOT funded the installation of the state’s first two automated, continuous in-street bicycle counters. These counters, which monitor bicycle traffic around the clock, 365 days per year, will provide new insights into the bicycle traffic volumes and their daily and seasonal patterns. While bicycle traffic monitoring in Minnesota is only in its infancy, it represents progress towards establishing the evidence base we need to determine how to make bicycling safer and to invest in bicycle infrastructure.
And so celebrate this Bike to Work Day and thank your fellow Minnesotans for all they have accomplished. But also take time to reflect on the work that needs to be done to improve opportunities for cycling throughout the state, for we have miles to go.
Greg Lindsey is a professor at the University of Minnesota Humphrey School of Public Affairs. His areas of specialty include environmental planning, policy, and management. His current research involves studies of the relationship between the built environment and physical activity, specifically factors that affect the use of pedestrian and cycling infrastructure. Lindsey presented some of his bicycle and pedestrian data collection research at the 2014 Minnesota Transportation Conference held March 4-6.
What if something as simple as changing the texture of the pavements we drive on could not only increase safety, but also reduce noise pollution and boost our vehicles’ fuel economy?
It’s possible, according to the latest research from MnROAD, the state’s one-of-a-kind pavement research facility. In a new report, investigators detail how quieter pavement textures, such as those applied by grinding grooves into pavements with diamond-coated saw blades (see the photo above), may also reduce rolling resistance — the force that resists a tire as it moves across the pavement’s surface.
The potential benefits to the public are significant. A 10-percent reduction in rolling resistance could reduce the U.S. public’s fuel consumption by 2–3 percent, eliminate up to $12.5 billion in fuel costs each year (as well as cutting carbon emissions). Add on the cost savings from reducing noise pollution (building noise barriers along highways can cost as much as $3 million per mile), and it’s clearly a win-win situation.
In the study, researchers used an innovative line-laser profiler to develop three-dimensional representations of test pavement surface textures. They then investigated the relationship between these surface characteristics and data on rolling resistance that was collected during a 2011 study using a special test trailer developed by researchers in Poland. This year, the same trailer will be used to conduct a second round of rolling resistance measurements at MnROAD.
The research is related to an ongoing pooled-fund study on concrete pavement surface characteristics. The goal is to produce data that will allow MnDOT to identify ideal ranges for surface characteristics that improve pavements’ quietness and ride quality while keeping them safe and durable.
Learn more
Pavement Texture Evaluation and Relationships to Rolling Resistance Final Report (PDF, 2.9 MB, 136 pages) and Technical Summary (PDF, 1 MB, 2 pages)
PCC Surface Characteristics – Rehabilitation Final Report (PDF, 2.8 MB, 104 pages) and Technical Summary (PDF, 1 MB, 2 pages)
Researchers relied on rolling resistance data from a study conducted in 2011 with a test trailer developed by the Technical University of Gdańsk, Poland. This was the first time such measurements were taken in the United States.
The Topeka shiner, a small minnow that inhabits slow-moving prairie streams, was once widespread and abundant in portions of Iowa, Kansas, Minnesota, Missouri, Nebraska and South Dakota. It now inhabits less than 10 percent of its original geographic range. (Photo courtesy of the Minnesota Department of Natural Resources)
In a new study funded by the Minnesota Department of Transportation, engineers are trying to ensure that new culverts do not degrade the habitat of an endangered fish in southern Minnesota.
The state has already researched how to better accommodate fish passage at river and stream crossings. Now it is looking at design guidelines for culverts that specifically impact the Topeka shiner, a small endangered fish found in five Midwestern states.
In Minnesota, the Topeka shiner is known to live in at least 57 streams, totaling 605 miles, within the Big Sioux and Rock River watersheds.
“The Topeka shiner is reported to have been erased from about 50 percent of its historic range in Iowa and much of its range in Minnesota, which is why Minnesota is so intent on doing what it can to help this fish thrive here,” said Alan Rindels, MnDOT’s project coordinator for the research.
The Topeka shiner is endangered due to the degradation of stream habitat, stream channelization, non-native predatory fishes and construction within waterways.
Culverts might impede the passage of this small minnow for a number of reasons, including that they might be too long, lack sufficient depth or carry water too fast.
Culverts (also called small bridges) allow water to pass under roads. Occasionally, they can harm a stream’s fish habitat by inadvertently acting as a barrier to fish passage or migration. On the West Coast, large-scale efforts are under way to protect migratory salmon, and in Minnesota, culvert designers are concerned about fresh water species.
In addition, long culverts block sunlight, which possibly discourages fish from swimming through. Typically, older culverts are replaced with longer culverts to improve road safety and minimize maintenance costs. To eliminate or minimize impacts to the Topeka shiner, the state is trying to determine if light mitigation strategies are necessary.
Researchers from the University of Minnesota’s St. Anthony Falls Research Laboratory will monitor a newly installed culvert (110 feet in length) and a few other culverts in critical Topeka shiner habitat streams during spawning and fall movement.
Additionally, a laboratory-based light manipulation experiment will examine the behavior of the warm-water fish when presented with a dark culvert.
Guidelines for culvert design in Topeka shiner habitat will be developed based on these results, as well as examples from neighboring states. The state is also collaborating with the U.S. Fish and Wildlife Service and affected Minnesota counties.
Minnesotans have grown accustomed to roundabouts as they’ve proliferated throughout the state, but many motorists are still confused by the less common two-lane roundabout.
While roundabouts have been shown to reduce vehicle delay and severe crashes, the few Minnesota cities with this type of multi-lane roundabout have had a prevalence of driver mistakes.
In Woodbury, two such roundabouts were converted into smaller, one-circulating-lane designs due to driver confusion.
The City of Richfield had no such option at the high-volume Portland Avenue and 66th Street, a formerly signalized intersection that carries about 30,000 vehicles per day. (See video)
Crash-prone and congested prior to its reconstruction in 2008, a two-lane roundabout seemed to be the practical solution for this intersection. But although the roundabout reduced overall crashes, the intersection still had more fender benders than designers were comfortable with, according to City Engineer Kristin Asher.
“The crashes were primarily related to improper left-turns from the outside lane and failure to yield at the entry,” she said.
Not only were drivers unsure which lanes they should use to enter or exit the roundabout, they didn’t know how to respond to other cars inside the roundabout. (See news story)
“People don’t understand they have to yield to both lanes inside the roundabout,” explained University of Minnesota researcher John Hourdos.
The city of Richfield extended the solid lines leading up to the intersection from 50 to 250 feet to encourage drivers to choose the correct lane before entering the roundabout. It also replaced fish-hook-style roundabout signs with traditional lane designation signs and did away with complex striping patterns.
Before and after photos show the original fish-hook style pavement markings, left, that were replaced with a more traditional design. (Courtesy City of Richfield)
Hourdos examined two years of traffic data to see how motorists responded to the improvements that were made in 2011.
He found 50 percent more drivers entered the correct lane from the get-go, which led to a reduction in improper turns within the roundabout. Lane violations were also reduced by 20 percent.
“One of the main problems was drivers didn’t know they have to choose one of the two lanes,” Hourdos explained. “Then once they were inside the roundabout, they were forced to either deviate from their course or commit a violation.”
The city also increased sign visibility to address yielding problems; however, these changes didn’t seem to make a difference.
With state and federal guidelines lacking much guidance for how to sign two-lane roundabouts, the LRRB is funding a new study for three other multi-lane roundabouts: in St. Cloud, at Highway 169/494 and one planned for the future realignment of County Roads 101 and 61 between Chanhassen and Shakopee.
Manual field counts require more labor than automatic technologies, but they can collect deeper data about demographics and helmet use. Both forms of monitoring are necessary to give a complete picture of bicycle and pedestrian traffic in the state.
To prepare for a multimodal future, state agencies must be able to plan and engineer a transportation system for all modes of transportation, including bicycle and pedestrian traffic.
The Minnesota Bicycle and Pedestrian Counting Initiative was launched to develop consistent methods for monitoring non-motorized traffic across the state. Researchers developed guidelines for manual counts using state and national examples, and they also created methods for extrapolating annual traffic volumes from short-duration automated counts, for integration into MnDOT’s vehicular count database program.
The guidance developed for manual counts includes forms, training materials, public information for passers-by, links to smartphone applications that provide counting locations and spreadsheets for reporting results.
MnDOT hosted six workshops and a webinar to introduce local officials to the initiative and recruit participants for pilot field counts. Researchers then analyzed how these field counts could be used with existing automated counts to extrapolate daily or annual data.
MnDOT has installed some of the very first automated counting equipment on a state road — Central Avenue NE in Minneapolis (on the bike lane) and Highway 13 in Eagan (on a shoulder). As of 2012, six agencies in Minnesota counted non-motorized traffic (annual reports are available from the city of Minneapolis and Transit for Livable Communities), and even though comprehensive data is not yet available, Minnesota is a leader in this type of monitoring with more than 1,000 manual count locations and 32 automatic count sites.
Because of Minnesota’s experience, researchers collaborated with the National Cooperative Highway Research Program’s national Methodologies and Technologies for Collecting Pedestrian and Bicycle Volume Data research project, due for release in 2014, and contributed to the Federal Highway Administration’s effort to update its Traffic Monitoring Guide to include a chapter on non-motorized traffic.
It’s no secret that manufacturing plays a key role in driving economic growth, or that transportation is essential for the success of any manufacturing operation.
While the relationships among manufacturing, transportation, and economic growth have been studied on a large scale, there is often little dialogue between transportation organizations and the manufacturers themselves. A recently completed pilot study conducted jointly by the Minnesota Department of Transportation (MnDOT), the University of Minnesota Humphrey School of Public Affairs, and University of Minnesota Extension aims to address this communication gap.
The pilot project focused on 12 counties in southwest Minnesota, where more than 172 regional businesses were contacted for participation and 75 in-person interviews were completed with manufacturers, shippers, and carriers. During the interviews, participants were encouraged to focus their comments on high-value, low-cost improvements that MnDOT can address in the short term without over-promising projects that currently cannot be funded.
Participants identified the need for smooth pavements and wide shoulders, the value of advance warning lights at intersections with traffic signals, the importance of highway safety, and the challenges of maneuvering oversized vehicles through roundabouts, among others.
The research team is compiling the pilot study’s findings into a final report. In the meantime, MnDOT is working to address a number of the challenges and suggestions uncovered through the pilot program.
Read the full article in the December issue of Catalyst.
Crossroads 