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Current Issue | Previous Issues | Subscribe October 2006 - Vol. 4 No. 9

Policy & Planning

Access to Destinations Study publishes first research report

The first research report from the Access to Destinations study has been published by the Minnesota Department of Transportation. Access to Destinations: Development of Accessibility Measures by Ahmed El-Geneidy and David Levinson presents results of the authors’ work on developing clear measures of transportation performance and land use within the Minneapolis-St. Paul metropolitan area.

Levinson and El-Geneidy’s research explored several possible methods of measuring accessibility, and led them to develop a new approach, called place rank. This approach shares some similarities with other accessibility measures but is intended to overcome their limitations and deliver a more accurate picture of accessibility. One important feature of place rank is that it accounts for the number of opportunities that an individual passes over in one geographic zone when traveling to an opportunity in another zone.

Development of powerful and comprehensive accessibility measures is a major goal of the Access to Destinations Study. Levinson and El-Geneidy’s work is expected to serve as a base for future research projects that will measure accessibility via different travel modes across the metro area.

In the process of developing and verifying their accessibility measurements, the researchers uncovered connections between measured accessibility and economic factors such as home sale values. These findings confirm the importance of accessibility as a way of understanding the complex relationships between transportation, land use, and regional economic performance.

David Levinson, one of the lead researchers in the Access to Destinations Study, is an associate professor in the University of Minnesota’s Department of Civil Engineering. His research and teaching interests include transportation technology, policy issues, and understanding processes of transportation network growth. Ahmed El-Geneidy is a post-doctoral research fellow in civil engineering and in the Hubert Humphrey Institute of Public Affairs, where his research focuses on transit operations, advanced traffic management systems, and urban transportation planning. Both Levinson and El-Geneidy are members of the CTS Faculty and Research Scholars.

Access to Destinations: Development of Accessibility Measures is available from the CTS Web site.

Politics and Freeways report published

Politics and Freeways, a new publication that reports on a study of the changing politics and participants in Twin Cities–area interstate decision making since the 1950s, is now available.

The project was jointly sponsored by the Center for Urban and Regional Affairs (CURA) and CTS, and was advised by an expert committee including former Minnesota Department of Transportation (Mn/DOT) commissioner and CTS director Richard Braun and former Mn/DOT officials Peter Fausch and Jim Newland.

The report was written by Patricia Cavanaugh, a Ph.D. candidate in the Department of Political Science and a research assistant at CURA.

“Transportation systems cannot be planned, developed, or implemented without contending with the politics in which they are always embedded,” Cavanaugh noted during a presentation of her findings at the CTS Seventeenth Annual Transportation Research Conference, held May 24–25 in St. Paul.

Cavanaugh examined local cases representing different eras in the history of the interstate program. The era that launched the interstate in the 1950s was a period of great optimism and public support; the protest era of the 1960s and 1970s, in contrast, saw the rise of citizen opposition and environmental advocacy. The Minnesota Legislature also became more involved in major transportation project decisions during this time. The next—and current—era is known by many as the “era of falling behind.”

Cavanaugh focused on seven case studies spanning five decades, from which she identified three areas of political tension. First, major projects take decades, but citizens and elected officials operate under a shorter outlook. Second, state DOTs look at a broader geographic area than do cities and neighborhoods. And third, citizens may define a problem in terms of social or moral aspects whereas Mn/DOT defines it in terms of reducing congestion.

For more coverage of Cavanaugh’s presentation and the panel discussion that followed, see the July issue of the CTS Report at www.cts.umn.edu/news/report/2006/07/.

Politics and Freeways: Building the Twin Cities Interstate System was jointly published by CURA and CTS. The report is available online at www.cts.umn.edu/publications/reports. A limited number of print copies are also available from CURA.

Safety & Security

SECTTRA program launches Web site

The Security and Transportation Technology Research and Applications (SECTTRA) program recently launched a Web site (www.secttra.umn.edu) to provide information about its work on new tools and techniques to address transportation security issues.

SECTTRA is a joint program of the University of Minnesota’s Department of Computer Science and Engineering (CSE) and the Center for Transportation Studies (CTS), and is led by Professor Nikolaos Papanikolopoulos of CSE.

Papanikolopoulos’s own research is focused on the areas of robotics, computer vision, and sensors for transportation applications. Currently, he is engaged in the development of small, semi-autonomous mobile units capable of monitoring large public areas while moving around on ceilings and walls. Other researchers affiliated with SECTTRA are tackling a variety of transportation security challenges, including evacuation planning and operations, remote sensing networks, and unmanned aerial vehicles.

The SECTTRA Web site features links to information on numerous security-related transportation research projects at the University of Minnesota, along with information on researchers and news about the program.

Intelligent Transportation Systems

Narrow commuter vehicle research could increase highway capacity

As traffic congestion continues to worsen in metropolitan areas, researchers are looking for new ways to increase the carrying capacity of urban freeway systems. Researchers at the University of Minnesota’s Department of Mechanical Engineering think their design for a narrow commuter vehicle could help solve congestion problems by fitting twice as many individual vehicles into the width of a single regular lane. The three-wheeled vehicle incorporates a novel computer-controlled stability system, allowing it to turn without tipping at highway speeds despite its short axle width and upright seating position.

Associate professor Rajesh Rajamani, a member of the research team, gave a presentation on the development of the prototype vehicle at an ITS Institute Advanced Transportation Technologies Seminar October 10, 2006. The project was led by research fellow Lee Alexander and included professor Patrick Starr and graduate students Jesse Gohl and Samuel Kidane. A research report on the project was also published by the Intelligent Transportation Systems Institute.

In his presentation, Rajamani highlighted the challenge of developing a control system that would tilt the vehicle like a motorcycle automatically in response to steering input from the driver, thereby counteracting the centripetal force that would otherwise tend to destabilize a relatively tall, narrow vehicle when turning. The problem of automatic tilt control is further complicated by the need to operate seamlessly at both low speeds (in city traffic) and at high speeds (on the freeway).

One of the main innovations in the vehicle control system lies in how it handles tilting and turning, based on a dynamic model of vehicle movement developed by the researchers. Rather than interpreting steering input directly as a request to change direction and then deriving the proper degree of tilt to maintain stability, the system treats a movement of the steering control as a request to tilt the vehicle. Once the tilt is accomplished, the change in direction follows automatically.

Solving these problems required the researchers to develop a “steer-by-wire” control system that relies entirely on computer-controlled servomotors to guide the vehicle, instead of a direct mechanical connection between the steering control and the wheels. The computerized system is able to control tilt by counter-steering—steering slightly opposite the direction of a desired turn—causing the vehicle to lean into the turn and change direction smoothly. While this may seem counterintuitive, a similar technique is used unconsciously by cyclists as they lean into turns.

The final project report presents a detailed explanation of the dynamic model and the mathematical simulations used to develop and test it, along with a description of the experimental test vehicle and its implementation of the control system. Development of a Novel Tilt-Controlled Narrow Commuter Vehicle (CTS 06-05) is available from the CTS Web site.

Transportation Infrastructure

Engineers, soil scientists delve into subgrade moisture effects

Hidden beneath the surface, subgrade soils have important effects on the durability and ride quality of the roads built on top of them. Traditionally, road engineers have looked at soil density when evaluating the quality of soils as a base for road construction. However, density alone does not guarantee stiffness and strength. To build a more complete picture of the factors affecting subgrade performance, University of Minnesota researchers are examining the effects of moisture on the behavior of subgrade soils.

In the Department of Civil Engineering, a research team led by associate professor Bojan Guzina, with co-investigator Joseph Labuz, recently completed an evaluation of the effects of density and moisture on the stiffness of several Minnesota soils. Professor Satish Gupta of the Department of Soil, Water, and Climate takes a somewhat different approach, focusing on mechanical properties. The studies are reflective of ongoing efforts to create solid links between design specifications and construction practices, thus furthering the mechanistic-empirical approach to pavement design.

An important aspect of Guzina and Labuz's research was the team’s effort to uncover the relationships between measurements made with field equipment and results obtained in the laboratory. Field testing using devices such as the portable vibratory deflectometer and the dynamic cone penetrometer is an important component of quality control for road construction. Seasonal variations in soil stiffness are commonly analyzed using these devices, with implications for setting seasonal load limits. Their report, Moisture Effects on PVD and DCP Measurements (Mn/DOT 2006-26) is available on the Mn/DOT Web site.

Satish Gupta takes a different approach to understanding moisture effects in subgrade soils. His work focuses on understanding the mechanical properties of soils, with the goal of developing a pavement design method that is consistent with the mechanistic-empirical design framework put forward by the Minnesota Department of Transportation (Mn/DOT) and American Association of State Highway and Transportation Officials (AASHTO) but is based on the principles of unsaturated soil mechanics.

Gupta presented his ongoing research to an audience of CTS Research Council members and fellow researchers at a CTS Research Seminar on September 11. Rather than empirically unifying the data derived from various test methods, Gupta is working to create a system that directly predicts the shear strength and modulus of subgrade materials based on their observed characteristics. More information on his research is available on his project page on the CTS Web site.

Transit & Alternative Modes

CTS to lead non-motorized transportation program's research, evaluation, and outreach

CTS has been selected to lead the overall program evaluation of the Non-motorized Transportation Pilot Program (NTPP), which was authorized by Congress in the 2005 transportation bill. The work consists of the data-collection and analysis phases as well as several outreach activities.

The pilot program provides funding to four communities—Columbia, Missouri; Minneapolis, Minnesota; Marin County, California; and Sheboygan County, Wisconsin—to construct a network of non-motorized transportation facilities. It also affords a unique learning opportunity for researchers and other communities.

Robert Johns, director of CTS, will provide interdisciplinary leadership and overall coordination for this effort. The technical aspects will be led by two faculty leaders at the University of Minnesota: Kevin Krizek, associate professor of urban planning and public affairs in the Humphrey Institute of Public Affairs, and Ann Forsyth, professor and director of the Metropolitan Design Center in the College of Architecture and Landscape Architecture. They will be advised by Susan Handy, associate professor at the University of California at Davis, and Kelly Clifton, assistant professor at the University of Maryland. Johns, Krizek, and Forsyth will be assisted by Laurie McGinnis, associate director of CTS, who will provide project coordination, liaison, and reporting to the pilot communities and the Federal Highway Adminsistration (FHWA).

The pilot communities will provide a living laboratory for research often called for, but rarely conducted, in policy circles: a before-and-after investigation to demonstrate to other communities across the country the specific merits of investing in non-motorized infrastructure. “Of immeasurable importance to the effort,” says Krizek, “is the creation of a careful protocol that will collect data, analyze such data, and communicate the findings from all four communities in a consistent manner, in order to cast a clear and compelling message to policymakers, analysts, and the public.”

The project team will also work with the NTPP Working Group to synthesize the research findings into a high-quality communications product appropriate for elected officials, policymakers, planners, and other audiences. This product will make a direct connection between the research and the NTPP legislation, a critical first step in moving from the project team’s technical evaluation to implementing the lessons learned from the NTPP. The synthesis, which will be published by CTS in the spring of 2011, will draw from the findings in all four communities.

Announcements

Braun Chair reaches fundraising goal; David Levinson named inaugural chair

The three-year fundraising campaign for the Richard P. Braun CTS Chair in Transportation Engineering has reached its goal of $500,000 in private and industry support. Braun is the founding director of CTS and a former commissioner of the Minnesota Department of Transportation (Mn/DOT).

The selection committee for the Braun CTS Chair was unanimous in recommending that Associate Professor David Levinson, a CTS Faculty Scholar, be appointed the inaugural chair. The appointment will be effective fall semester 2006, says John Gulliver, head of the civil engineering department. He also announced that the funds available for the Braun CTS Chair allow the department to expand its transportation engineering faculty. A search will begin this fall for a new faculty member.

The Braun CTS Chair in Transportation Engineering is a leadership position that will build on the legacy started by Professor Matthew Huber. Under Levinson’s leadership, the transportation engineering program will be expanded to include a combination of the following:

• New undergraduate courses in transportation and traffic planning, design, and engineering
• New short courses for professionals in transportation and traffic planning, design, and engineering
• A series of seminars or workshops at various locations for government and private sector transportation engineers

“David Levinson’s reputation as an academic scholar is well known in the department, with numerous journal publications and three books published,” says Gulliver. “What is not well known is his commitment to students, which is demonstrated through his role as the founding faculty advisor to the Interdisciplinary Transportation Student Organization (ITSO).”

ITSO grew to more than 300 student members in two years and is active with five professional organizations related to transportation in Minnesota. “ITSO is now capable of bringing transportation professional groups together,” Gulliver added, “and they are all benefiting from David’s work with the student chapter.”

Toward Zero Deaths Conference November 2-3

The 2006 Toward Zero Deaths Conference will be held November 2 and 3 in Duluth. The conference provides a venue to share best practices in the areas of engineering, enforcement, education, and emergency services, as well as to chart the course for a future with fewer traffic fatalities and life-changing injuries.

Sponsors are the Minnesota Departments of Public Safety and Transportation and the Minnesota Toward Zero Deaths Program. The conference is being hosted by CTS and facilitated by the College of Continuing Education at the University of Minnesota.

A brochure with a detailed program schedule and registration materials can be found on the TZD Web site (156 KB PDF). For more information, visit www.tzd.state.mn.us or contact Shirley Mueffelman, 612-624-4754, conferences2@cce.umn.edu.

Summaries of the 2004 and 2005 conferences, published by CTS, are available for download at www.cts.umn.edu/publications.

Call for Presentations: 2007 research conference

CTS has issued a Call for Presentations (152 KB PDF) for its Eighteenth Annual Transportation Research Conference. The call invites all interested individuals to submit a one-page abstract for a presentation (or poster) at the conference, to be held May 1–2, 2007, at RiverCentre in St. Paul.

If you or your organization would like to share the results of your efforts in transportation-related fields, please submit an abstract by November 15.

All abstracts must be submitted electronically. Go to the CTS Web site at www.cts.umn.edu/events/rescon and follow the instructions to submit your abstract.

For further information, contact Electra Sylva at conferences5@cce.umn.edu or 612-624-3708.

CTS Councils will meet this winter to review abstracts and finalize the conference sessions.

Upcoming Events

Here are selected events related to transportation research. Visit the CTS Web site, www.cts.umn.edu/events, for more comprehensive event information. You may also subscribe to e-mail event announcements using our subscription form.

November 2-3, 2006
Toward Zero Deaths Conference, Duluth, Minnesota. Call Shirley Mueffelman, 612-624-4754, conferences2@cce.umn.edu. [More]

November 2, 2006
CTS Research Seminar: Capacity Expansion in the Twin Cities: The Roads-Transit Balance, Minneapolis, Minnesota. Contact Chad Rathmann, rathmann@cts.umn.edu. [More]

November 7, 2006
Advanced Transportation Technologies Fall Seminar: Portable Video Data Processor, Minneapolis, Minnesota. Contact Stephanie Malinoff, 612-624-8398, malinoff@umn.edu. [More]

November 8, 2006
CTS Research Seminar: Exercise Medicine Study for 'Destination Exercise,' Minneapolis, Minnesota. Contact Chad Rathmann, rathmann@cts.umn.edu. [More]

November 14, 2006
CTS Fall Luncheon, Minneapolis, Minnesota. Contact Electra Sylva, 612-624-3708,
conferences5@cce.umn.edu.

November 21, 2006
Advanced Transportation Technologies Fall Seminar: Collective Responsibility in Freeway Rear-end Collisions - An Application of Causal Models, Minneapolis, Minnesota. Contact Stephanie Malinoff, 612-624-8398, malinoff@umn.edu. [More]

December 1, 2006
Freight and Logistics Symposium, Minneapolis, Minnesota. Contact Electra Sylva, 612-624-3708, conferences5@cce.umn.edu.

December 5, 2006
Advanced Transportation Technologies Fall Seminar: VII Communications, Minneapolis, Minnesota. Contact Stephanie Malinoff, 612-624-8398, malinoff@umn.edu. [More]

May 1-2, 2007
18th Annual CTS Transportation Research Conference, RiverCentre, St. Paul. Contact Electra Sylva, 612-624-3708, conferences5@cce.umn.edu.