Why the best laid plans sometimes go astray

Forecasting travel demand is a necessary part of planning for transportation system improvements, and a variety of tools and techniques have been developed to estimate of future demand. University of Minnesota researchers David Levinson, the CTS/R.P. Braun chair in transportation engineering, and Pavithra Parthasarathi examined the accuracy of transportation demand forecasts using a sample of recently completed projects in Minnesota. Using both qualitative and quantitative approaches, their work highlights factors influencing overestimation and underestimation of future travel demand. The research was sponsored by the Minnesota Department of Transportation (Mn/DOT).

The researchers’ preliminary analysis indicated a general trend toward underestimating future travel demand, particularly in projects dealing with freeways and other high-functional-classification roadways. Quantitative analysis of completed transportation projects drew attention to several factors influencing forecast accuracy. Qualitative analysis was employed to investigate the reasons for inaccuracies from the modeler’s perspective.

Gathering historical information on traffic demand models for past projects proved to be one of the most challenging aspects of the research. In light of these difficulties, the researchers’ final report recommends that transportation agencies adopt procedures for collecting and preserving data related to travel demand estimation as part of the project planning process.

In addition, the researchers suggest that a better understanding of the modeling process and its limitations would enable administrators to make more informed decisions about the allocation of funds to transportation projects.

Post-Construction Evaluation of Forecast Accuracy (Mn/DOT 2009-11) is available from the CTS Web site.

Journal of Transport and Land Use

CTS is pleased to announce the publication of the Winter 2009 issue of the Journal of Transport and Land Use, available at http://jtlu.org.

The Journal of Transport and Land Use is an open-access, peer-reviewed online journal publishing original interdisciplinary papers on the interaction of transport and land use. Domains include: engineering, planning, modeling, behavior, economics, geography, regional science, sociology, architecture and design, network science, and complex systems.

Contents:
Access, Aging, and Impairments Part A: Impairments and Behavioral Responses
Jan-Dirk Schmöcker, Tokyo Institute of Technology

Access to Public Transit and Its Influence on Ridership for Older Adults in Two U.S. Cities
Daniel Baldwin Hess, University at Buffalo, State University of New York

Mode Choice of Older People Before and After Shopping: A Study with London Data
Fengming Su, Jan-Dirk Schmöcker, and Michael G.H. Bell, Imperial College, London

Determinants of Residential Location Decisions among the Pre-Elderly in Central Ohio
Hazel A. Morrow-Jones and Moon Jeong Kim, The Ohio State University

The Challenge of Using Public Transport: Descriptions by People with Cognitive Functional Limitations
Jenny Rosenkvist, Ralf Risser, Susanne Iwarsson, Kerstin Wendel, and Agneta Ståhl, Lund University, Sweden

Book Review: Urban Structure Matters, by Petter Naess
Xueming Chen, Virginia Commonwealth University

Intelligent Transportation Systems

STAR sheds light on technology-transportation connections

University of Minnesota researchers recently concluded a six-year study of the connections between transportation and the information and communication technologies that permeate the modern world. The Sustainable Technologies Applied Research (STAR) project examined a wide range of issues including travel behavior, emergency services, and modeling techniques.

The project’s principal investigators included Richard Bolan, Lee Munnich, and Kevin Krizek of the Hubert Humphrey Institute of Public Affairs’ State and Local Policy Program (Krizek is now at the University of Colorado); Humphrey Institute visiting scholar Thomas Horan; and David Levinson, the Richard P. Braun/CTS Chair in Transportation Engineering, from the civil engineering department. Their research was supported by the ITS Institute through a grant from the U.S. Department of Transportation’s Research and Innovative Technologies Administration.

In order to examine transportation and technology from multiple perspectives, the STAR project encompassed several independent studies that examined different questions. Findings from these projects are integrated in a final summary report.

Among the key issues examined by the STAR researchers were potential methods of implementing and paying for new technologies that affect transportation, the effects of information and communications technologies on commercial development and transportation, the potential for connection between private innovators and public entities, and the possible impacts of information technologies on privacy and freedom in the transportation arena.

Additional contributors to the STAR research included: Mark Berndt, Richard Burkhard, Frank Douma, Chandler Duncan, Susan L. Handy, Andrew Johnson, Ugur Kaplancali, Ramachandra Karamalaputi, Adam Kokotovich, James Lehnhoff, Yi Li, Michael Marich, Denise McCabe, Pavithra Parthasarathi, Benjamin Schooley, Colbey Sullivan, Ryan Wilson, Peng Xu, Bhanu M. Yerra, and Lei Zhang.

Places and Networks: The Changing Landscape of Transportation and Technology (CTS 08-15), the final technical report of the STAR project, is available from the ITS Institute Web site.
A summary of findings from the STAR project is also available from CTS.

Transit, Bicyling, 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’s Role in Addressing Global Climate Change (TCRP Research Results Digest 89)
• Transit Security Update (TCRP Synthesis 80)

Safety

Gonna make it home tonight: researchers study effects of sleep deprivation on truck drivers

From Bakersfield to Nashville, truck drivers’ long hauls are the stuff of country music legend. But fatigue is a significant problem for truckers—and everyone else who eschews rest in order to get to their destinations sooner. To better understand the effects of sleep deprivation, John Bloomfield and Kathleen A. Harder of the Center for Human Factors Systems Research and Design and graduate student Benjamin Chihak carried out a series of tests on commercial motor vehicle (CMV) drivers using the HumanFIRST Program’s advanced driving simulator. The ITS Institute supported this research through a grant from the U.S. Department of Transportation’s Research and Innovative Technologies Administration.

Twenty drivers recruited with the aid of the Minnesota Trucking Association were each kept awake for the entire 20-hour experiment. Each participant drove for four one-hour sessions (morning, afternoon, evening, and night) in the simulator, which presented a variety of features and road characteristics along a route that took roughly an hour to drive. The subjects also took visual performance and reaction time tests. Following the experiment, all participants were taken to a supervised location to catch up on their shut-eye.

Although forbidden to nap, the drivers were allowed to consume caffeine and tobacco if they would normally do so.

Data collected during the experiment showed that the drivers’ steering was less steady after sleep deprivation, indicating that even experienced CMV drivers are likely to experience some performance impairment if they are kept awake for a long time.

The Effect of Sleep Deprivation on Driving Performance (CTS 09-03) is available from the ITS Institute Web site.

Transportation Infrastructure

Searching for the state of the art in bridge deck sealing

Bridge deck sealants and crack sealers can add years to the life of concrete bridge decks. With funding from the Minnesota Department of Transportation (Mn/DOT) and the Minnesota Local Road Research Board (LRRB), researchers in the University of Minnesota’s civil engineering department—graduate student Karl Johnson, professors Arturo Schultz and Catherine French, and researcher Jacob Reneson—conducted a study to find the current state of the art in bridge deck and crack sealing.

In cold climates, the use of deicing chemicals during the winter months subjects roads and bridges to potentially heavy salt damage. Effective deck and crack sealing protects bridge decks by reducing the penetration of chloride ions into the concrete. Steel reinforcing bars embedded in the concrete are highly susceptible to damage by chloride penetration; in addition to weakening the rods themselves, corrosion causes expansion of the metal rods that further damages the surrounding concrete.
The research included a review of research literature on deck and crack sealing, analysis of a Mn/DOT survey of transportation agencies around the country to determine common sealing practices, and a review of the results of deck sealant studies conducted in Minnesota.

Based on the results of these studies, the final report recommends sealants that provide good protection against chloride penetration. The report also includes general recommendations for sealant testing, selection, and application.

Crack and Concrete Deck Sealing Performance (Mn/DOT 2009-13) is available from the CTS Web site.

Announcements

In memoriam: Barbara Lukermann

Barbara Lukermann, a former CTS Scholar, passed away March 22 after a short but intense bout with cancer. For more than 25 years, Lukermann was a senior fellow and faculty member in the planning program of the Humphrey Institute of Public Affairs. She also helped found the University’s Center for Urban and Regional Affairs (CURA), where she was a senior research associate. Her research focused on land development, metropolitan planning, and the links among land use, housing, and transportation policy. She was much loved for her kindness and her devotion to her community, the planning profession, and her students and colleagues.

During her career, Lukermann influenced state and regional policy through her work in organizations such as the Minnesota Environmental Quality Board and the Governor's Roundtable on Sustainable Development. She chaired the American Institute of Certified Planners, the Metropolitan Waste Control Commission, and St. Paul's District Energy utility, and served as president of the Citizens League.

Lukermann was involved in a number of CTS research, education, and outreach initiatives over the years, including the Transportation and Regional Growth Study. She received numerous awards, including the 2001 Richard P. Braun Distinguished Service Award from CTS and the 2004 American Planning Association award for distinguished leadership by a professional planner.

Also in her honor, the Humphrey Institute annually presents the Barbara L. Lukermann Service Award to students in the planning degree program for exceptional contributions to the planning community. And on March 31, the Humphrey Institute dedicated the Lukermann Conference Room in her recognition. Dean Brian Atwood, Professor Ed Goetz, former student Barbara Sporlein, and Professor Tom Scott of CURA shared remarks about Lukerman's many contributions to the Institute.

CTS Transportation Research Conference

The 20th Annual CTS Transportation Research Conference May 19–20 will feature a presentation and discussion of findings from the Access to Destinations Study, a keynote address by New York Times best-selling author Tom Vanderbilt, and a Bridge Workshop covering technologies for structural monitoring. The conference will be held May 19–20 at a new location: the Sheraton Bloomington Hotel in Minneapolis. Online registration and program information is available on the CTS Web site.

The opening session—“Destinations Count”— will include a presentation of findings from Access to Destinations Study co-leaders David Levinson, the Richard P. Braun/CTS Chair in Transportation Engineering, and Kevin Krizek, an associate professor at the University of Colorado (previously with the University of Minnesota’s Hubert H. Humphrey Institute of Public Affairs).

Access to Destinations is an interdisciplinary research and outreach effort coordinated by CTS that takes a new approach to understanding how people use the transportation system and how transportation and land use interact.

The implications of the findings will then be discussed by a panel of transportation experts: Tim Henkel, modal planning and program management division director with the Minnesota Department of Transportation; Curt Johnson, president of Citistates Group; and Mariia Zimmerman, vice president for policy with Reconnecting America, a national organization focused on the link between transportation and community development.

The conference luncheon on May 19 will feature a presentation by Tom Vanderbilt, the author of Traffic: Why We Drive the Way We Do (and What It Says About Us). Vanderbilt’s talk, “Objects in Mirror Are More Complicated Than They Appear,” will present highlights from his book related to the dynamics of traffic flow, the social interactions of drivers, the perceptual illusions and cognitive biases that humans behind the wheel are prone to, and the relationship between the built environment and our behavior, among other aspects of this complex—yet overlooked—everyday activity.

The conference’s Bridge Workshop will include results from a University of Minnesota study comparing different types of technology and systems for monitoring critical structural components, as well as updates about the instrumentation incorporated into the new I-35W bridge.

The program and registration information are available online. For more information, contact Sara Van Essendelft, 612-624-3708, cceconf5@umn.edu.

Research Partnership Award

A system to monitor the performance of urban arterials and improve traffic flow received this year’s CTS Research Partnership Award, and special recognition was given to a study of pervious concrete. Dawn Spanhake, CTS assistant director for program and financial management, presented the award at the CTS Annual Meeting and Awards Luncheon held March 25. The annual award recognizes research projects within the CTS program that have resulted in significant impacts on transportation, and rewards teams of individuals who have drawn on the strengths of their diverse partnerships to achieve those results.

SMART-Signal (short for “Systematic Monitoring of Arterial Road Traffic Signals”)—is a real-time arterial performance monitoring system that uses traffic data from existing signal systems. The project was a joint effort of the University, Hennepin County, Mn/DOT, and the private sector. The research was funded by the Intelligent Transportation Systems (ITS) Institute at CTS and the Minnesota Local Road Research Board, with significant in-kind support from Hennepin County.

Henry Liu, an assistant professor in the Department of Civil Engineering, accepted the award on behalf of the project partners. Although traffic engineers have tools to measure real-time freeway performance, he said, similar approaches for urban arterials do not exist but are urgently needed. The development of SMART-Signal fills in this gap. “We can do much better to manage traffic...if we have the right tools.”

In their research, Liu and his students developed software and hardware to collect and archive data—about vehicles, signals, and pedestrians—and calculate real-time performance measures. At the single-intersection level, SMART-Signal can calculate the maximum queue length on a cycle-to-cycle basis, from which other measures such as intersection delay and level of service can be calculated. At the arterial level, SMART-Signal can report travel time, speed, and average number of stops in real time. The system contributes to scientific knowledge and also “has practical value to traffic engineers,” he said.

SMART-Signal has been instrumented on 11 intersections along France Avenue in Hennepin County since February 2007 and on six intersections of Mn/DOT Trunk Highway (TH) 55 since January 2008; another test site with 14 intersections will be instrumented on TH 13. The research team’s evaluation found that system performance compares well with real-world data, Liu said. Results from an independent evaluation on TH 55 are also very encouraging. Continuing research is focused on enhancing the system to allow automatic signal adjustment based on traffic conditions.

The University is currently in the patent application process to protect the intellectual property, Liu said. He also noted that his team has received a grant from the National Cooperative Highway Research Program to extend their work on SMART-Signal, and that the system is used as an education module in a civil engineering course at the University.

Project Partners:

• University of Minnesota, Department of Civil Engineering: Henry Liu, Wenteng Ma, Xinkai Wu, Heng Hu
• Hennepin County: Eric Drager, James Grube, Roy Doron, Darryl Dobesh, Tom Switzer
• Alliant Engineering: Bob Green
• Mn/DOT: Steve Misgen, Ronald Christopherson, Mike Dittel, Shirlee Sherkow

Spanhake also gave special partnership recognition to one other project: “Pervious Concrete Research in Minnesota.” This project brought together the Department of Civil Engineering, Mn/DOT, the City of Shoreview, Holcim USA, Cemstone, and Iowa State University’s Concrete Pavement Technology Center. The purpose of the project was to study the performance of pervious concrete for cold climates and develop suitable mix designs and construction practices. The research has so far shown that by good construction practice, materials selection, and pavement design, pervious pavements can be built in freeze-thaw-intensive climates.

Project Partners:

• Mn/DOT: Bernard Izevbekhai (also with University of Minnesota, Department of Civil Engineering), Benjamin J. Worel, Bruce Holdhusen
• University of Minnesota, Department of Civil Engineering: Lev Khazanovich
• City of Shoreview: Mark Maloney
• Holcim USA: Joe Clendenen
• Cemstone: Kevin MacDonald
• Iowa State University Concrete Pavement Technology Center: Paul Wiegand

More Upcoming Events

April 25–29
American Planning Association National Planning Conference, Minneapolis, MN.

April 30
TH-36 Full Road Closure: Lessons for the Future; John Hourdos. 2:30–3:30 p.m. CST; Room 1130, Mechanical Engineering Building. Seminars also will be broadcast live on the Web and available for later viewing.

May 1
The Future of Transportation Funding and Financing Alternatives Summit. Crowne Plaza Minneapolis North Hotel, Minneapolis, MN.

May 19
CTS Spring Luncheon featuring Tom Vanderbilt, author of Traffic: Why We Drive the Way We Do (and What It Says About Us), Sheraton Hotel, Bloomington, MN. Contact Sara Van Essendelft, 612-624-3708, cceconf5@umn.edu.

May 19–20
20th Annual CTS Transportation Research Conference, NEW LOCATION: Sheraton Hotel, Bloomington, MN.

June 1–3
ITS America's 2009 Annual Meeting & Exposition, National Harbor, MD.

June 15–16
International Transport Economics Conference: Incorporating the International Conference on Funding Transport Infrastructure, Minneapolis, Minnesota.

June 18–20
1st Transatlantic NECTAR (Network on Communications and Transport Activities Research) Conference, Arlington, Virginia.