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Current Issue | Previous Issues | Subscribe November 2007 - Vol. 5, No. 10

New features on CTS Web site: search engine, research topics, and more

The CTS Web site now offers several new ways to find information. You can browse research projects and reports by topic. It’s a quick way to find University of Minnesota research on subjects ranging from bridges to economics.

Another new feature is the Minnesota Transportation Search Engine, which uses Google Custom Search to search all transportation-related Web sites in Minnesota. You can also try the other customized search engines to search the Web sites of all LTAP centers, university transportation centers, state DOTs, or metropolitan planning organizations.

Since the redesign of the Web site, launched last February, usage has nearly quadrupled over the same time period during the previous year. Check out these helpful tools on the CTS Web site.

Policy and Planning

Second Access to Destinations conference features national and international research perspectives

Like its predecessor, the second Access to Destinations Conference held this past August featured research findings from around the world. This time, however, speakers also shared examples of how accessibility measures are being put into practice.

This CTS-sponsored conference came nearly three years after the inaugural gathering, explained Robert Johns, CTS director, in his opening remarks. That event helped launch the Access to Destinations Study, an interdisciplinary research and outreach effort led by David Levinson and Kevin Krizek to measure accessibility for the Twin Cities region. Levinson is an associate professor and Braun/CTS Chair of Transportation Engineering at the University of Minnesota; Krizek is an associate professor at the University of Colorado (and was previously with the Hubert H. Humphrey Institute of Public Affairs). CTS is coordinating the study with support from sponsors including the Minnesota Department of Transportation, Hennepin County, the Metropolitan Council, and the McKnight Foundation. For more information, see www.cts.umn.edu/access-study.

The public portion of this year’s conference began with international perspectives on accessibility, moderated by John Adams, associate dean of the Humphrey Institute. Adams was a key researcher in the Transportation and Regional Growth Study, an earlier CTS-led effort.

Among the highlights of the general sessions were presentations by several leading transportation and land-use researchers:

• Kay Axhausen of the Institute for Transport Planning and Systems at the Swiss Federal Institute of Technology traced the evolution of transportation and land use patterns in Switzerland.
• Hong K. Lo, professor of civil engineering at the Hong Kong University of Science and Technology, examined Hong Kong’s model for integrating public transit with compact development.
• Robert Bruegmann, professor of art history, architecture, and urban planning at the University of Illinois at Chicago, examined the history of suburbanization and sprawl and its implications for the future of urban development.

The three researchers then participated in a panel discussion of the implications for research and practice, moderated by Johns. They were joined by Levinson and Krizek, co-organizers of the conference, and two national experts: Sam Seskin, transportation planning director with consultant CH2M Hill, and Anne Canby, president of the Surface Transportation Policy Project.

The conference continued with a day and a half of technical presentations for invited participants. A summary of the conference will be available from CTS later this year. Selected conference papers will be published in the Journal of Transport and Land Use, a new journal under development by Levinson and Krizek with assistance from CTS.

Expanded coverage of the general conference sessions is available online in the October 2007 CTS Report.

Intelligent Transportation Systems

A new solution to a slippery winter problem

From fender-benders to fatal pile-ups, ice on roads contributes to thousands of crashes every winter. But a new sensor system for snowplows, developed by researchers from the University of Minnesota’s mechanical engineering department, could help keep ice off roads and confined to hockey rinks where it belongs. The project was supported by the Minnesota Department of Transportation.

Graduate students Gurkan Erdogan and Piyush Agrawal worked with research fellow Lee Alexander and professor Rajesh Rajamani to design a truck-mounted system for measuring tire-road friction coefficients; these measurements are then used to control the application of sand or de-icing chemicals. Designed to be mechanically simple and reliable, the device relies on advanced signal-processing techniques to measure friction as a snowplow moves at standard plowing speeds.

The research employed the ITS Institute’s SAFEPLOW research vehicle—an operational snowplow equipped with a suite of driver-assistive systems—as a testbed.

The new system measures the forces acting on a separate, small wheel mounted near the front axle of a snowplow. The wheel is skewed slightly relative to the direction of vehicle travel, so a lateral force is always present. This force is measured by a load cell, and the variations in force measurements are analyzed by a processing unit to determine when to trigger the release of sand or de-icing chemicals.

Two key challenges in developing this system proved to be filtering out the large amount of noise in the signal coming from the wheel, and compensating for the effects of turns and speed changes on the friction measurements. The researchers developed a filtering algorithm incorporating a biased quadratic mean filter and an accelerometer-based vibration filter in order to remove extraneous signals and quickly estimate the friction coefficient.

With minimal moving parts and no actuators, the system is designed to be more reliable and less expensive than the Norse meter that has been traditionally used to monitor slippery road conditions. Real-time friction measurement offers important benefits, such as reducing the amount of chemicals that must be applied to provide a safe road surface. More effective use of chemicals means lower operating costs as well as less groundwater pollution from salt and other de-icing agents.

A final report on the project, Automated Winter Road Maintenance Using Road Surface Condition Measurements (Mn/DOT 2007-37), is available from the CTS Web site.

Transit, Bicycling, and Walking

TCRP research publications available online

The federal Transit Cooperative Research Program (TCRP), administered by the Transportation Research Board, provides practical transit research to address technical and operational issues. TCRP emphasizes putting research results into the hands of organizations and individuals that can use them to solve problems.
Recent TCRP publications include:

• Public Transportation Passenger Security Inspections: A Guide for Policy Decision Makers (TCRP Report 86, Vol. 13)
• The Americans With Disabilities Act (ADA): The Federal Transit Administration’s (FTA’s) Letters of Findings and Compliance Assessments (TCRP Legal Research Digest 23)

Transportation and the Environment

Biological control of a thorny pest

Canada thistle (Cirsium arvense) is a common invasive plant species that is classified as a noxious weed by many states where it occurs, including Minnesota. Because it outcompetes many native prairie species for light and nutrients, controlling Canada thistle is a priority for many agencies. The species is common in roadside ditches, where it thwarts the efforts of transportation agencies to establish native prairie vegetation.

Researchers at the University of Minnesota’s Department of Agronomy and Plant Genetics suggests new possibilities for controlling this thorny pest. Professor Donald Wyse and graduate student Kari Eichstaedt examined how a common phytopathogenic bacterium, Pseudomonas syringae, infects Canada thistle under different conditions. Their findings could lead to new management practices that discourage the growth of Canada thistle. The research was supported by the Minnesota Department of Transportation.

Eichstaedt conducted field experiments to determine what factors favor bacterial infection of the thistles, and whether native grasses could create conditions that favored such infections. The researchers concluded that dense stands of perennial grasses were detrimental to Canada thistle infestations, and should be included in roadside vegetation establishment projects or wetland restorations.

Biological Control of Canada Thistle in Wetland Prairie Restoration (Mn/DOT 2007-38) is available from the CTS Web site.

Safety

Evacuation research nets additional federal funds

Shashi Shekhar, a McKnight Distinguished University Professor of computer science, in collaboration with Henry Liu, a civil engineering assistant professor, recently received a grant titled “Spatio-temporal Network Databases for Transportation Science” from the National Science Foundation (NSF). The grant is to further research into scalable computational methods for determining routes, schedules, and traffic management plans for evacuating metropolitan areas. Both Shekhar and Liu are CTS Faculty Scholars.

Two years ago Shekhar’s research team completed a system to coordinate local emergency evacuation plans in multiple communities. The system is designed to minimize potential congestion on major roadways, speed up the evacuation process, and maximize safety for citizens.

The goal was to create a tool that would run more efficiently than the standard linear programming approach and allow users—such as transportation professionals and first responders—to quickly find the best escape routes, even for large scenarios. The result was a capacity-constrained route planning system with a simple, Web-based user interface.

The Minnesota Department of Transportation used the software to develop a metro evacuation traffic management plan for the Twin Cities area. Seventy public and private agencies in the nine-county metro area were invited to create the plan. Their effort was honored with the CTS Research Partnership Award in 2006.

Since then Shekhar has been refining his capacity-constrained routing software to make it more accessible and easy to use for the private sector. To learn more about his research, visit the CTS Research pages.

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 20

ITS Institute Advanced Transportation Technologies Seminar: School Travel and the Implications for Advances in Transportation-Related Technology, 3:00–4:30 p.m, 1130 Mechanical Engineering Building, Minneapolis. More

November 26

CTS Research Seminar: SMART-SIGNAL: Systematic Monitoring of Arterial Road Traffic and Signals, 8:30–10:30 a.m., 1130 Mechanical Engineering Building, Minneapolis. More

November 30

11th Annual CTS Freight and Logistics Symposium: Freight Planning in an Uncertain World, Minneapolis. Contact Julie Grazier, 612-624-3708, cceconf5@umn.edu. More

December 11

Access to Destinations Study Workshop, 3:00–4:30 p.m., 1130 Mechanical Engineering Building, Minneapolis. More

February 13, 2008

CTS Winter Luncheon, Radisson University Hotel, Minneapolis. "The Future of Vehicle Safety," Ronald Medford, National Highway Traffic Safety Administration. Contact Julie Grazier, 612-624-3708, cceconf5@umn.edu. More