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Congratulations to soon to be Dr. Carlos Carrion (shown in the center of the picture, between alums Nebiyou Tilahun and Pavithra Parthasarthi), who recently defended his Ph.D. Thesis "Travel Time Perception Errors: Causes and Consequences" (a draft of which is linked). He is working as a post-doctoral researcher at MIT/SMART in Singapore.

Travel Time Perception Errors: Causes and Consequences

Abstract:

This research investigates the causes, and consequences behind travel time perception. Travel times are experienced. Thus, travelers estimate the travel time through their own perception. This is the underlying reason behind the mismatch between travel times as reported by a traveler (subjective travel time distribution) and travel times as measured from a device (e.g. loop detector or GPS navigation device; objective travel time distribution) in collected data. It is reasonable that the relationship between subjective travel times and objective travel times may be expressed mathematically as: Ts = To + ξ. Ts is a random variable associated with the probability density given by the subjective travel time distribution. To is a random variable associated with the probability density given by the objective travel time distribution. The variable ξ is the random perception error also associated with its own probability density. Thus, it is clear that travelers may overestimate or underestimate the measured travel times, and this is likely to influence their decisions unless E(ξ) = 0, and Var(ξ) ≈ 0. In other words, travelers are “optimizing” (i.e. executing decisions) according to their own divergent views of the objective travel time distribution.

This dissertation contributes novel results to the following areas of transportation research: travel time perception; valuation of travel time; and route choice modeling. This study presents a systematic identification of factors that lead to perception errors of travel time. In addition, the factors are related to similar factors on time perception research in psychology. These factors are included in econometric models to study their influence on travel time perception, and also identify which of these factors lead to overestimation or underestimation of travel times. These econometric models are estimated on data collected from commuters recruited from a previous research study in the Minneapolis-St. Paul region (Carrion and Levinson, 2012a, Zhu, 2010). The data (surveys, and Global Positioning System [GPS] points) consists of work trips (from home to work, and from work to home) of subjects. For these work trips, the subjects’ self-reported travel times, and the subjects’ travel times measured by GPS devices were collected. Furthermore, this dissertation provides the first empirical results that highlight the influence of perception errors in the valuation of travel time, and in the dynamic behavior of travelers’ route choices. Last but not least important, this dissertation presents the most comprehensive literature review of the value of travel time reliability written to date.

Nexus alumnus, Shanjiang Zhu was just appointed to an assistant professor position at the Civil, Environmental, and Infrastructure Engineering Department in the Volgenau School of Engineering at George Mason University.

CEIE Welcomes Dr. Shanjiang Zhu | GMU CEIE:

The CEIE Department is pleased to welcome Dr. Shanjiang Zhu to the CEIE Department in August 2012. Dr. Zhu obtained his doctorate from the Department of Civil Engineering, University of Minnesota, in 2010, and extended his research in transportation planning and engineering as a research scientist at University of Maryland for two years. His research interests include agent-based travel demand models, integrated models of micro-simulation and macroscopic demand models, applications of GIS/GPS in transportation modeling, sustainable transportation, and transportation economics. He enhances the current curricula by integrating problem-oriented teaching philosophy with his research experience in various transportation-related projects, especially those with immediate applications in addressing local transportation problems. Dr. Zhu is currently teaching the Introduction to Transportation Engineering (CEIE 360). He looks forward to working with CEIE students both in the classroom and on transportation-related research projects."

Nexus alumnus, and new father, Nebiyou Tilahun was recently appointed to an assistant professor position at the University of Illinois at Chicago:

Dr. Tilahun is currently an Assistant Professor in the Department of Urban Planning and Policy at the University of Illinois at Chicago. He received his Ph.D. from the University of Minnesota in 2010. His research interests are in transportation planning, travel behavior, the study of travel for social activities, and the use of agent based models for transportation planning applications. His dissertation, Matching Home and Work: Job Search, Contacts and Travel, developed a framework for work trip distribution from the perspective of the job search process. Between May 2009 and December 2011, he successively held postdoctoral researcher positions at the Urban Transportation Center (UIC) and the Hubert Humphrey School of Public Affairs (UMN) working on issues related to Job Access and Reverse Commute and Human Services Transportation (at UIC), and linking transit accessibility to the regional economy in the Twin Cities (at UMN). As a graduate student he was a member of the NeXuS research group. Previously he also worked as a Transportation Engineer at the Washington State Department of Transportation (2001-2002). Dr. Tilahun's Civil Engineering studies started in Ethiopia at Addis Ababa University’s Faculty of Technology. During the Fall of 2012 he will be teaching UPP 502 Planning Skills: Computers, Methods and Communications and UPP 562: Urban Transportation III: Laboratory.

Congratulations to Nexus alumnus (and new father) Lei Zhang, (now at the University of Maryland) who was granted an NSF Young Faculty CAREER Award for the project Reliability as an Emergent Property of Transportation Networks

Abstract: The objective of this Faculty Early Career Development (CAREER) Program award is to investigate how individual travel behavior (e.g., route choice, trip scheduling, and selection of transportation mode) and transportation-related organizational decision-making (e.g., investment and pricing decisions) impact travel reliability (percentage of on-time arrival at destination). This research tests the hypothesis that minor behavior changes at the individual or organizational level leads to significant changes in travel reliability. The theory explains how individuals and organizations actually make transportation-related decisions, recognizing that they do not have perfect information or unlimited computational capabilities. The empirical portion of the research addresses a gap in the transportation science literature by employing smart phones as mobile GPS sensors to collect travel behavior data.

If successful, this project will provide decision-support tools that could help transform transportation systems operations and planning practices. These tools will enable transportation agencies to assess strategies that induce individual and organizational behavioral changes (e.g., increased transit ridership, improved trip departure time choice, better route diversion decisions, and more cost-effective transportation investments) that could mitigate traffic congestion and improve travel reliability. Over the long run, a more efficient and reliable transportation system will stimulate economic growth, enhance quality of life, and support emergency response. As this research breaks traditional disciplinary boundaries between the behavioral sciences and systems engineering, it also sets the stage for a new research direction that focuses on optimizing transportation system performance based on how choices are actually made, not how they should be made. This project will involve high school undergraduate, and graduate underrepresented students in various research tasks. Research findings will be broadly distributed through a K-12 Transportation Education Web Portal, an open-access Wiki site, and other professional and community outreach efforts.

Lee Munnich passes on news that famed transportation economist, Herb Mohring, passed away on June 4. His biography in wikipedia is below:

Herbert Mohring: "Herbert Mohring was a transportation economist who taught at the University of Minnesota from 1961-1994. He received his Ph.D. from Massachusetts Institute of Technology in 1959.

He is widely known for his identification of what was dubbed the Mohring effect of increasing returns in public transportation (see: Mohring (1972) for details).

Mohring and Harwitz (1962) also showed that the revenues from the first-best congestion tax exactly cover the construction costs of highways when highways possess constant returns to scale.

Important Works

• Mohring, Herbert, Optimization and Scale Economies in Urban Bus Transportation, American Economic Review 62, no. 4 (September 1972): 591-604.


• Mohring, Herbert, The Peak Load Problem with Increasing Returns and Pricing Constraints, American Economic Review 60, no. 4 (September 1970): 693-705.


• Mohring, H. and Harwitz, M., Highway Benefits: An Analytical Framework, Ch 2, pp 57–90. (1962)"

Much of his widely cited scholarly work can be accessed here.

A review of a paper extending Mohring's work: Cost recovery from congestion tolls with random capacity and demand and risk aversion by Robin Lindsey was given at the session in honor of Herb Mohring International Transport Economics Conference. June 16, 2009.

A policy presentation by Herb's friend David Lewis presented at the same session: America's Traffic Congestion Problem: Toward a Framework for Nationwide Reform.

Update 6/15/2012: Obituary published in Star Tribune.

Jessica Schoner just received an honorable mention from APA's Transportation Planning Division for her paper (which was a class term paper (technically 2 term papers), not a thesis or dissertation!): Shifting Gears: A cross-regional analysis of bicycle facility networks and ridership. A Reviewer said: "Of all the years doing this contest this is by far the best on bicycling I've seen." If you care about network structure, or about travel behavior, or about bicycles, read it.

Jessica Schoner has a blog: Network Distance - Thoughts about transportation, GIS, and life.

Congratulations to soon to be Dr. Pavithra Parthasarathi, who recently was awarded the 2011 John S Adams Award for Excellence in Transportation Research and Education, and who successfully defended her Ph.D. Thesis "Network Structure and Travel" (a draft of which is linked) on May 5, 2011. She accepted a job with the Hampton Roads Transportation Planning Organization (HRTPO) in Norfolk, VA, starting May 16th.

Abstract:

Changing the design aspects of urban form is a positive approach to improving transportation. Land use and urban design strategies have been proposed to not only to bring about changes in travel behavior but as a way of providing a better quality of life to the residents. While the research on the relationship between urban form and travel behavior has been pretty extensive, there is a clear gap in the explicit consideration of the underlying transportation network, even though researchers acknowledge its importance. This dissertation aims to continue on the research interest in understanding travel behavior while explicitly accounting for the underlying transportation network structure.

Transportation networks have an underlying structure, defined by the layout, arrangement and the connectivity of the individual network elements, namely the road segments and their intersections. The differences in network structure exist among and between networks. This dissertation argues that travelers perceive and respond to these differences in underlying network structure and complexity, resulting in differences in observed travel patterns. This hypothesized relationship between network structure and travel is analyzed in this dissertation using individual and aggregate level travel and network data from metropolitan regions across the U.S. Various measures of network structure, compiled from existing sources, are used to quantify the structure of street networks. The relation between these quantitative measures and travel is then identified using econometric models.

The underlying principle of this research is that while the transportation network is not the only indicator of urban form and travel, an understanding of the transportation network structure will provide a good framework for understanding and designing cities. The importance of such an understanding is critical due to the long term and irreversible nature of transportation network decisions. The comprehensive analyses presented in this dissertation provide a clear understanding of the role of network design in influencing travel.

Since it is now officially out, congratulations to Laurie McGinnis, who is no longer "acting".

Date: July 7, 2010

To: CTS Committee Members

Fr: Robert J. Jones, Senior Vice President for System Academic Administration
Andrew Furco, Associate Vice President for Public Engagement

Re: Appointment of Director for Center for Transportation Studies

We are pleased to inform you that Ms. Laurie McGinnis has been appointed as the new Director of the Center for Transportation Studies (CTS), effective July 5, 2010. This appointment is the result of a comprehensive national search process that included a review of 19 well-qualified applicants from throughout the country.

As Director of CTS, Ms. McGinnis will provide leadership, direction, and vision in achieving the mission of the Center, which includes advancing innovations that put the University at the forefront of transportation research. She will facilitate the work of more than 100 contracts totaling more than $20 million, which engage faculty and other transportation experts in conducting research that addresses some of today's most important transportation issues. Ms. McGinnis will also provide support and leadership to two federally funded programs that operate within CTS: the ITS Institute, a National University Transportation Center (UTC), and the Minnesota Local Technical Assistance Program (Mn LTAP).

Ms. McGinnis has been involved in the transportation field since 1984. Over the last 18 years, she has been a key player in the development and growth of CTS, having served as the Center's Research Coordinator, Director of Research and Contract Management, Associate Director, and Acting Director. Through her previous leadership experiences at CTS she has created new program opportunities that have expanded the Center's national reach, helped streamline operations, and articulated future directions in transportation research, education, and outreach.

Nationally, Ms. McGinnis is active in the Transportation Research Board, currently serving as Section Chair for the Research and Education Section, and recently completed a six-year term as chair of the Committee on the Conduct of Research. She is also a member of Women's Transportation Seminar (WTS), serving on the Steering Committee for the joint WTS/DOT initiative for advancement of Science, Technology, Engineering, and Mathematics (STEM). She has previously held positions on the National Board of Directors, the International Advisory Board, and the local WTS Minnesota Chapter Board.

Ms. McGinnis holds a Bachelor of Science degree in Civil and Environmental Engineering from the University of Wisconsin and two Masters degrees (in Public Affairs and Business Administration) from the University of Minnesota. She is a registered engineer in Minnesota and Wisconsin. Before coming to the University, she was a project manager at HNTB, where she participated in the design of several bridges for state and local agencies.

I just found out that professor Paul Wright, who taught me the Introduction to Transportation Engineering course at Georgia Tech, passed away.

The transportation professoriate has a lost a number of giants in the past two years:

• David Forkenbrock of Iowa,
  
• Ed Sullivan of Cal-Poly San Luis Obispo,
  
• Ryuichi Kitamura of Kyoto and Davis,
  
• Reg Golledge of UCSB,
  
• Charles Lave of Irvine, and
  
• Tom Maze of Iowa State.
  

(updated 6/23 w. Reg Golledge, 6/24 w/Charlie Lave)