Category Archives: Research

General research posts.

Why do men and women travel differently? Study sheds light on gender differences

Despite their more similar roles at work and home than ever before, U.S. men and women continue to have different travel behavior. Historically, employed men have spent more time traveling to work and less time on household and family support trips than women. While this difference is well-documented, explanations for the difference vary widely: some theories say it’s due to biologically driven differences in gender, while others attribute it to socially constructed gender roles or to gendered structural contexts such as labor market segregation and economic inequality.

While much research has examined these theories, few studies have tested their validity based on evidence—which prompted U of M researchers to examine the theories more deeply. “We believe a greater understanding of the underlying reasons for these enduring travel differences is necessary to effectively address the gender equity issue in transportation policy,” says Yingling Fan, assistant professor in the U’s Humphrey School of Public Affairs.

Researchers set out to test the competing theories by analyzing publicly available data from the American Time Use Survey (ATUS) in various ways across groups of workers with different types of family structures. (ATUS is an ongoing time diary study funded by the U.S. Bureau of Labor Statistics.)

First, they tested the theory that travel behavior differences were based on biologically driven gender differences. “If this theory was true, travel differences between men and women could be applied across all population groups regardless of family structure, but this was not the case,” Fan explains. “We found that single female workers and single male workers exhibit no significant difference in travel behavior.”

Next, the team studied the impact of gendered structural contexts, such as women’s greater presence in pink-collar occupations and significantly lower earnings. The team found moderate support for this theory. “These factors are associated with shorter work travel time among some—but not all—family structures,” Fan says.Shopping

Researchers did find strong support, however, for the theory that socially constructed gender roles explain travel behavior differences. “We discovered that while marriage alone doesn’t differentiate travel behavior between men and women, parenthood does have a significant impact,” Fan says. “Interestingly, we found that even being the sole breadwinner does not insulate mothers from socially constructed gender roles—female breadwinners in married single-worker households with children have shorter work commutes and more household support travel than male breadwinners in the same family structure.”

According to the researchers, these findings have important implications. First, policies to minimize auto travel (for environmental purposes, for example) may be unfair to women who wish to reach more job possibilities through longer commutes. In addition, the findings highlight the importance of incorporating parenthood as a prime variable in understanding the gender and mobility connection.

Finally, this research provides insights on how future growth or decline in specific family structures may shape travel demand. “As childless households continue to grow in relation to households with children, it’s possible that fewer female workers will be confined by short work commutes and may choose to spend more time commuting to more desirable jobs, placing new demands on the transportation system,” Fan says.

The research was funded in part by a Minnesota Population Center Program Development Grant.

Reprinted from the May 2014 issue of CTS Catalyst.

CTS Transportation Research Conference Wrap-Up (Photo Gallery)

The 25th Annual CTS Transportation Research Conference successfully concluded earlier today, wrapping up a two-day whirlwind of more than two-dozen sessions showcasing a wide range of transportation research results and innovations.

Presentations and materials from the conference, including video of the keynote speakers, will be made available on the CTS website in coming weeks. In the meantime, here are a few photos from the conference.

Center for Transportation Studies Director Laurie McGinnis
Center for Transportation Studies Director Laurie McGinnis welcomes attendees to the 25th Annual CTS Transportation Research Conference in St. Paul, Minnesota, on May 21, 2014.
MnDOT Chief of Staff Eric Davis
MnDOT Chief of Staff Eric Davis: “Research is vital to our program. It’s vital to our success as a department.”
Joe Casola, staff scientist and program director for the Center for Climate and Energy Solutions
Joe Casola, staff scientist and program director for the Center for Climate and Energy Solutions, gives the keynote address on Wednesday. Casola said transportation officials should begin incorporating the projected impacts of climate change, including more frequent extreme weather events, into their planning.
MnROAD Operations Engineer Ben Worel
On Wednesday, MnROAD Operations Engineer Ben Worel moderated a session, “Building the Future on a Solid Foundation,” focused on geotechnical research.
MnDOT Research Services & Library Director Linda Taylor and MnDOT Planning and Data Analysis Director Mark Nelson
From left: MnDOT Research Services & Library Director Linda Taylor and MnDOT Planning and Data Analysis Director Mark Nelson answer questions at a session on transportation pooled-fund research projects.
Jill Hentges, community outreach coordinator for Metro Transit
Jill Hentges, community outreach coordinator for Metro Transit, displays a tool used to help teach the public how planners optimize bus routes during a Thursday session on public engagement. Angie Bersaw, a transportation planner for Bolton & Menk, Inc., looks on.
Bruce Hasbargen, Beltrami County engineer and Local Road Research Board chairman
Bruce Hasbargen, Beltrami County engineer and Local Road Research Board chairman, answers a question at a Wednesday session on local agencies and stakeholder engagement.

Bike to Work Day: progress in Minnesota, but miles to go

By Greg Lindsey

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.

MnDOT library director recognized for ROI work

One may not think of librarians as having a crucial role in the building of a road, bridge or trail, but in the state of Minnesota, they do.

Each day, the MnDOT Library locates obscure-but-important information for engineers and transportation practitioners, such as the safety aspects of extra-tall concrete median barriers, the travel patterns of blind pedestrians and the environmental impact of treated lumber used on freeway noise walls.

“I like to say, ‘Google gets the easy stuff and we get the really difficult stuff,’ ” said Sheila Hatchell, MnDOT Library Director, who was recently recognized with an Innovation Award from the Special Libraries Association’s Transportation Division for helping transportation libraries demonstrate the value of this work.

Proving Your Library's Value: A Toolkit for Transportation Libraries
Proving Your Library’s Value: A Toolkit for Transportation Libraries

With few good examples to follow, Hatchell and two peers set out to develop a national guidebook for quantifying the benefits of a special library, in particular a transportation library.

“There is a wealth of studies demonstrating the value of public and academic libraries, but when it came to special libraries, there was almost nothing,” Hatchell said. “And what little there was, it didn’t pertain to state transportation libraries.”

Hatchell spent her weekends researching what other institutions have done and drafting much of the 52-page toolkit, “Proving Your Library’s Value,” which was published in early 2013 through the Transportation Library Connectivity and Development Pooled Fund Study.

Soon after, MnDOT put her work into practice, hiring a consultant through the department’s research program to perform a Return-On-Investment (ROI) study on the library.

2013 MnDOT Library Valuation/Return On Investment (ROI) Study Findings
2013 MnDOT Library Valuation/Return On Investment (ROI) Study Findings details the tangible and intangible savings realized from MnDOT’s library.

The study determined that for every $1 spent, the library produced nearly $2 worth of value — mostly due to the dollar value of research that might otherwise be provided by a paid consultant. The dollar figure doesn’t include the intangible value such information provides transportation projects.

In 2012, the MnDOT Library responded to more than 2,100 requests for information — many which took days or weeks to track down. They also loaned out nearly 3,800 items, routed 10,887 journal issues and distributed more than 560 journals and books borrowed from other libraries.

“A lot of people use the library and don’t even know it,” Hatchell said, since much of the data is shared with a wider audience.

Hatchell was asked to speak about her research this week at the Texas Library Association Annual Conference.

Helpful Resources

MnDOT Library ROI study

“Proving Your Library’s Value” national guidebook

 

MnDOT announces research implementation projects

Minnesota’s next round of research implementation projects will reduce the spread of noxious weeds along state highways, improve the quality of asphalt on Minnesota roads and enhance the inspection of state bridges.

MnDOT’s Transportation Research Innovation Group (TRIG) has announced 15 projects for funding in Fiscal Year 2015. (Project descriptions below.)

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

“Certain departments have problems they’ve been working on for a long time and they’ve spun their wheels or not had the staff resources to get something done,” said MnDOT Research Services & Library Project Advisor Bruce Holdhusen, who helps employees develop their proposal plans.

One implementation project: Further testing and demonstration of portable traffic control devices (auto flaggers) to increase their usage by highway maintenance crews.
One implementation project will complete testing and demonstration of portable traffic control devices (auto-flaggers) to increase their usage by highway maintenance crews.

MnDOT provides the funding needed for equipment, consultant services or researcher assistance. Supervisors also must sign off that they’ll make time for the staff member to implement the practice.

“Implementation means it’s changing the way some practitioner does their job,” Holdhusen said. “It’s not just trying something new; it’s got to stick.”

Highlights of this year’s projects:

  • Installation of GPS units on MnDOT mowers to alert highway maintenance crews to areas of noxious weeds. This is anticipated to cut herbicide usage in half.
  • Purchase of 3D sonar equipment for underwater bridge inspection, which is currently performed by engineer-divers.
  • Selection of an alternative, European-branded center-line rumble strip (Sinusoidal) that produces less stray highway noise.
  • Implementation of an innovative asphalt-quality test, developed by MnDOT’s Office of Materials and Road Research, to assess the cold temperature-cracking properties of asphalt mixes proposed by contractors.
  • Advertisement of state rest area amenities on highway notification signs. This pilot project will target 13 rest stops.

The complete list of projects, by category:

Environment
Maintenance Operations and Security
Materials and Construction
Multimodal
Bridge and Hydraulics
Traffic and Safety

MnDOT leaders highlight TRB benefits at forum

As a graduate student 35 years ago, Bill Gardner attended his first Transportation Research Board Annual Meeting, and he still remembers the thrill.

“I felt like a kid in a candy shop,” recalled Gardner, who heads MnDOT’s Office of Freight and Commercial Vehicle Operations. “I was amazed at the diversity of topics… You could find people who have devoted their whole lives to the hazards of rural mailboxes.”

Gardner and other MnDOT leaders on Tuesday recounted their experiences from this year’s annual meeting — which drew more than 10,000 participants — and encouraged other MnDOT staff to get involved in the organization, which helps set national transportation guidelines, oversees collaborative research and facilitates the exchange of information.

“We’re heavily involved, but I think we could be more involved,” said Modal Planning and Program Management Director Tim Henkel, who has been part of the TRB for more than 20 years.

Henkel said TRB involvement benefits MnDOT in several ways, including access to national and international experts, the ability to keep tabs on hot-button issues and having a seat at the table in decision-making.

“It makes us a more enlightened and informed decision-making body,” Henkel said.

MnDOT has more than 60 staff serving on 114 TRB committees and contributes $125,000 annually to the TRB core program, gaining $127 in collaborative research for every $1 it contributes.

“It’s a very intense and very busy experience," said Chief MnDOT Engineer Deputy Commissioner and Chief Engineer Sue Mulvihill, who displayed the thick program book and other materials from this year’s Transportation Research Board Annual Meeting.
“It’s a very intense and very busy experience,” said MnDOT Deputy Commissioner and Chief Engineer Sue Mulvihill, who displayed the thick program book and other materials from this year’s Transportation Research Board Annual Meeting.

As part of a series of staff forums they will hold throughout the year, MnDOT leaders chose to highlight the TRB, which met in January. (MnDOT employees interested in attending next year or getting involved in the TRB should speak with their supervisor.)

State Bridge Engineer Nancy Daubenberger, who serves on a TRB subcommittee and gave a presentation at the recent conference, said it helps to hear about the challenges faced by agencies around the country.

Assistant Engineering Services Division Director Amr Jabr, who attended for the first time, said he used a smartphone app just to decide which of the approximately 3,500 sessions he wanted to attend.

“I thought it was an extremely good experience,” he said. “I picked up a lot of information and made a lot of new contacts.”

Funding highway projects with value capture could speed project completion

There’s broad agreement that the U.S. transportation system cannot continue to be funded with existing financing and revenue-generation methods. What’s unclear, however, is how to pay for highway projects in the future. The current transportation funding system emphasizes user fees, but there is growing interest in alternative funding strategies. One promising strategy is value capture, which aims to recover the value of benefits received by property owners and developers as a result of infrastructure improvements.

In recent years, University of Minnesota researchers have helped lead the way in value capture research with a series of reports identifying value capture strategies. In a newly published study, the research team applied their previous work to a real-world scenario, with impressive results.

The new research, sponsored by the Minnesota Department of Transportation, focused on the planned development of Trunk Highway 610 (TH 610) in Maple Grove, Minnesota—a stretch of planned state highway delayed for years by state transportation funding shortages. Researchers set out to discover how the value of the enhanced accessibility provided by the planned improvements could be predicted and captured to help fund the project’s completion.

To accomplish their goal, researchers first defined a study area of about 10 square miles surrounding the unfinished highway segment. Then, they modeled property values based on five factors using parcel-level data. This model was designed to isolate the so-called “highway premium” by controlling for other factors that affect land value including water views, open space, railroads, transit stops, and existing highway exits. Using this model, researchers found significant evidence that the completion of the highway could lead to an over $17 million increase in property value.

Researchers expect these findings to have significant benefits for the TH 610 project and beyond.

Read the full article in the March issue of Catalyst.

Photo courtesy of SRF Consulting Group, Inc.

‘Smart window’ technology opens new possibilities for transportation noise control

Nearly every time a highway or airport expansion is proposed, transportation planners face opposition from residents who fear the increased noise levels in their homes and businesses. Traffic noise is often mitigated with physical noise barriers, but the large, thick walls often draw opposition as well.

A new technology developed by University
 of Minnesota mechanical engineering professor 
Rajesh Rajamani as part of 
a research project funded
 by the National Science
 Foundation could soon
 provide a nearly invisible
 solution for transportation 
noise cancellation—and 
give transportation planners another tool for overcoming project opposition.

Noise enters homes close to airports and highways primarily through windows, and windows can transmit ten times the sound energy as walls can, says Rajamani. With this in mind, researchers set out to reduce the amount of transportation noise transmitted through windows.

To accomplish this goal, researchers created a method of active noise control for windows. Active noise control works by using speakers to generate a sound wave that is a mirror image of the undesirable sound wave. Superimposing an “anti-noise” wave of the same amplitude as the undesirable noise wave results in a reduced decibel level of noise in the environment.

The research team began by designing thin, transparent speaker panels to fit in the empty space between the two panes of a double-pane window. Then, the researchers tested the effectiveness of the new speakers, using them to cancel out undesirable transportation noise from outside the home while preserving the desirable noise from inside the home.

In addition to mitigating traffic noise, this new technology offers other surprising benefits. Researchers have found that the “smart window” speakers can actually be used as home audio speakers without losing any of their noise-control benefits.

Read the full article in the February issue of Catalyst.

Innovative pavement textures reduce noise, improve fuel economy

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
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.
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.