Capacity Drop in Freeway Sags and Tunnels: Theory, Empirical Validation, and Control

Event Overview

This talk covers the theory, empirical validation, and control of the capacity drop phenomenon at sag and tunnel bottlenecks. We first overview a continuum theory of capacity drop at these bottlenecks, which clearly explains the connection between the bottleneck effect and the resulting capacity drop. The theory is then validated both qualitatively and quantitatively using empirical data from multiple sites in Japan. New control strategies for mitigating capacity drop are also introduced and compared. Finally, based on these insights, we discuss case studies on evaluating an existing control method and on designing a new control method grounded in the theoretical framework.

Dr. Kentaro Wada is an Associate Professor at the University of Tsukuba, Japan. He received his Ph.D. in Information Sciences from Tohoku University in 2013. His research covers a wide range of topics in transportation systems, including traffic flow theory with emphasis on capacity drop phenomena, dynamic equilibrium models of departure time and route choice, market-based demand management such as tradable network permits, and traffic signal optimization. Dr. Wada was a Visiting Scholar at UCI in 2017–2018.

Infrastructure Assisted Cooperative and Distributed Perception Strategies for Connected Vehicles

Abstract

This research addresses the challenge of efficiently processing sensor data across vehicles, edge, and cloud platforms to support resource-intensive perception tasks in autonomous driving.

We investigate distributed processing of perception data from three perspectives to enhance perception accuracy, optimize network and computing resources, and meet real-time latency constraints: (1) offloading computationally intensive tasks to edge or cloud platforms for greater processing capacity and reduced on-board load, (2) evaluating the impact of compression techniques such as H.265 and JPEG on perception quality and transmission latency, and (3) exploring feature-vector transmission as an alternative to raw or compressed data to reduce bandwidth usage while maintaining perception accuracy and minimizing end-to-end delay.

To evaluate performance under realistic conditions, the study utilized both simulation-based assessments and real-world experiments. Using Vehicle-to- Everything (V2X) communication technologies, we analyzed compression and feature-sharing strategies for seamless data exchange between vehicles and infrastructure. Our findings demonstrated that the proposed cooperative and distributed perception strategies significantly improved detection accuracy and reduced processing delays compared to standalone on-board systems.

Raphaël Frank is a Professor / Senior Research Scientist and Entrepreneur at the Interdisciplinary Centre for Security, Reliability and Trust (SnT), University of Luxembourg. He is the Head of the UBIX Research Group, which conducts research on distributed artificial intelligence. Since 2023 he is a member of the University of Luxembourg Council and adjunct Professor at HEC Liège Luxembourg. Since 2024 he is the director of the IPBG ATLAS Industrial PhD Program.

Meet Caltrans Directors

Event Overview

Lan Zhou is a 20+-year veteran of the California Department of Transportation (Caltrans). She currently serves as the Caltrans District 12 Director, where she previously served as Deputy Director of Planning and Local Assistance for eleven years, and before that as the Corridor System Management Program Manager and Regional Planning and Local Development Review Branch Chief. She began her Caltrans career in District 4 (Bay Area) as a lead engineer in Maintenance and Toll Bridge Engineering. Zhou has a long history in strategic planning, organizational excellence, and partnership building, and has a wide breadth of experience including working for universities, a Metropolitan Planning Organization (MPO), local government and multiple State Departments of Transportation. As the District 12 Director, Zhou leads
nearly 1,000 employees and serves 3.2 million residents.

Dina El-Tawansy has 23 years of service with Caltrans and her leadership experience spans three Districts and multiple Divisions. She is currently the District Director, Caltrans, District 4, Bay Area. Prior, she served as Chief Deputy District Director for Caltrans District 4. While much of her career has been in District 4 and District 7, Dina also served in District 12, Orange County, as the Deputy District Director of Operations and Maintenance. In her current capacity, Ms. El-Tawansy manages a $2 Billion budget of inhouse and oversight investments and leading nearly 3,500 staff. As Director of District 4, she implements the Department’s new Mission, Vision and Goals, builds and strengthens partnerships, and continues the work towards multimodal, safe and reliable transportation solutions that serve all people of the Bay Area. Dina possesses a B.S. degree in Civil Engineering from Cal Poly Pomona and an M.S. degree from Long Beach State University in Construction Management. She is a licensed Professional Engineer (PE) and Project Management Professional (PMP)

Multimodal Transportation System Design from a Regulatory Perspective

Event Overview

Public agencies are taking actions to promote multimodal transportation, while the emergence of multimodality raises challenges. With diverse service designs and
operational strategies, modeling, evaluating, and managing such systems from a holistic
perspective becomes more difficult.

Regulators require modeling tools capable of handling multiple stakeholders and various operational strategies. To incorporate different types of operational strategies, we extend the traditional
assignment game into a nonlinear mixed-integer programming model that integrates
both fixed-route and on-demand services.

The model captures decision-making from
both travelers and operators to form a market equilibrium and we propose a stochastic assignment game and define its core. We further adapted this approach into a stochastic Stackelberg game to model urban mobility markets, where the regulator is the leader and stochastic coalitions of travelers and operators form as the followers.

SPEAKER

Bingqing Liu received her Ph.D. in Transportation Systems at Tandon School of Engineering, New York University. She is currently a postdoctoral scholar at UCLA, affiliated with the Center of Excellence on New Mobility and Automated Vehicles. Her research focuses on network modeling of multimodal transportation systems, with game theory, operations research, and simulation approaches.

Markets for Road Use: Eliminating Traffic Congestion through Scheduling, Routing, and Real-Time Road Pricing

Event Overview

Traffic congestion is a pervasive worldwide problem. In this webinar. we explain how to harness existing technologies together with new methods in time-and-location markets to eradicate traffic congestion along with its attendant social harms. Our market design for road use builds on congestion pricing and models of efficient pricing in the electricity sector. The market maximizes the value of a transport network through efficient scheduling, routing and pricing of road use. Privacy and equity concerns are addressed. Transparent price information provides essential information for efficient long-term investment in transport.

Dr. Rick Geddes is currently a Visiting Fellow with the Hoover Institution at Stanford University, on a one-year sabbatical from his permanent position as professor in Cornell’s Jeb E. Brooks School of Public Policy and Professor of Economics at Cornell. He is Founding Director of the Cornell Program in Infrastructure Policy, or CPIP; is a member of the graduate fields of Systems Engineering, Regional Science, and Economics; and is a Non-Resident Senior Scholar at the American Enterprise Institute in Washington, DC.

Dr. Geddes research centers on funding, financing and delivery of major infrastructure projects, road pricing, and utility regulation. His publications have appeared in numerous academic journals and he authored the 2011 AEI book entitled, The Road to Renewal: Private Investment in U.S. Transportation Infrastructure. Dr. Geddes holds MA and Ph.D. degrees in economics from the University of Chicago, and a BS in economics and finance from Towson State University.

Capturing Freeway Congestion: What 100 Days of Data from 294 Cameras tell us

Event Overview

The Tennessee Department of Transportation’s I-24 Mobility Technology Interstate Observation Network (MOTION) is a four-mile section of I-24 in the Nashville-Davidson County Metropolitan area with 294 ultra-high definition cameras. Those images are converted into a digital model of how every vehicle behaves with unparalleled detail. This is all done anonymously using trajectory processing algorithms developed by Vanderbilt University. By unlocking a new understanding of how these vehicles influence traffic, vehicle and infrastructure design can be optimized to reduce traffic concerns in the future to improve safety, air quality, and fuel efficiency. For more details, data, and tools, visit i24motion.org.

SPEAKER
Junyi Ji is a PhD Candidate at Vanderbilt University working with Prof. Daniel B. Work. He is mainly focusing on the TDOT I-24 MOTION, a real-world freeway testbed generating billion-level vehicle trajectory data. His primary research focuses on the multi-scale dynamics of traffic waves. His research vision is to integrate computational methods and cyber-physical systems (CPS) for sustainable transportation solutions aligned with the UN Sustainable Development Goals (SDGs). He is a strong advocate for open science. He is the initiator of the workshop on vehicle trajectory data camp and actively volunteers with organizations such as RERITE, Citipedia, and MoveVU.

Decarbonizing Aviation: Cash-for-Clunkers in the Airline Industry

Abstract

The durability of the transportation capital stock slows down the pace of decarbonization since newer vintages feature cutting-edge technology.

If older vintages were to be retired sooner, the social cost of travel would decline. This paper analyzes and explores the viability of a potential cash-for-clunkers program for the airline industry, which would help to hasten decarbonization of aviation. Focusing on US aviation, our estimation and calculations show that airlines can be induced to scrap rather than sell older planes upon retirement with a payment that is less than the forgone carbon damage.

Jan K. Brueckner is Distinguished Professor of Economics at the University of California, Irvine.

He received a B.A. from UC Berkeley in 1972 and a Ph.D. from Stanford University in 1976, and was a long-time faculty member at the University of Illinois at Urbana-Champaign before coming to UCI in 2005. He has served as visiting professor at UC Santa Barbara and UC San Diego, and has been a visiting scholar at many foreign universities. Brueckner has published extensively in the areas of urban economics, public economics, housing finance, and the economics of the airline industry, with more than 160 papers published in refereed journals. He served as editor of the Journal of Urban Economics for 16 years (1991-2007) and is currently a member of the editorial boards of 8 journals. He is a Fellow of the Regional Science Association of the Air Transport Research Society and served as president of the International Transportation Economics Association. He has also served as a consultant to the World Bank, the US Department of Transportation, many of the major airlines, and other entities.

Human Spatial Navigation: Cognitive Graphs, Route Choice, and Individual Differences

Navigation is a central part of daily life. For some, getting around is easy, while others struggle. Some clinical populations, such as those with Alzheimer’s Disease, display wandering behaviors and extensive disorientation. Working at the interface between immersive virtual reality and neuroimaging techniques, my research uses these complementary approaches to inform questions about how we acquire and use spatial knowledge. In this talk, I will discuss both some of my recent work and current experiments that center on three main themes: 1) how we learn new environments, 2) how the brain tracks spatial information, and 3) how individuals differ in their spatial abilities. The studies presented in this talk inform new frameworks for understanding spatial knowledge, leading to novel approaches to answering the next major questions in navigation, learning, and memory.

Dr. Elizabeth Chrastil is an Associate Professor in the Department of Neurobiology & Behavior at UC Irvine, with an appointment in the Department of Cognitive Sciences, and is a fellow of the Center for the Neurobiology of Learning & Memory. She was awarded the Early Career Award from the Psychonomic Society in 2023. Dr. Chrastil received her PhD from Brown University and did her postdoctoral work at Boston University. She also received an MS in biology from Tufts University and a BA from Washington University in St. Louis.

Los Angeles Student Travel Behavior

High school students in the US generate a lot of travel, but their travel behavior has not been widely studied. We have administered a survey to high school students in Los Angeles to measure their travel behavior and examine their response to a new program (called GoPass) that provides free transit trips to any K-14 student in the Los Angeles metropolitan area. We examine students’ choice to sign up and use GoPass. Our survey includes a Stated Preference experiment to measure students’ value of time and their demand for new services such as robotaxis. This talk provides preliminary results from the survey and transportation choice models.

David Brownstone is an emeritus Professor of Economics at UCI. He has studied the impacts of tax reform on housing demand, the impacts of measurement errors in economic surveys, the impacts of carpool lanes and road pricing, the impacts of urban form on household vehicle choice and utilization, the demand for alternative-fueled vehicles, the economic impact of California’s rail system, and the demand for public transportation. In addition to his applied work, Brownstone was one of the first econometricians to apply bootstrapping and multiple imputations to generate valid inferences in complex models. Together with Kenneth Train and David Bunch he was one of the first to apply mixed logit models in household vehicle demand and transportation mode choice models. Brownstone currently serves on the editorial boards of Transportation Research (Part B: Methodological), Economics of Transportation, and The Journal of Choice Modeling.

Geographic Intelligence for Bridging Transportation Planning and Environmental Needs

The planning of linear transportation infrastructures, which for decades has followed the geometric design premises of highways and railways mainly in greenfield projects, currently faces significant challenges. These challenges include the need for a strong inclusion of socio-environmental perspectives, as well as a continuous analysis of the logistical and economic feasibility of the project considering the existence of an already operating transportation system. In this sense, this presentation will argue for the need to modernize transportation planning and promote ESG (Environmental, Social, and Governance) principles in current and future projects. Results of research projects on the topic will be presented, focusing on Transport Ecology, Geographic Modeling of Corridors of Technical, Economic, and Environmental Feasibility, geographical simulations of routes and micro-logistic basins based on changes in freight costs resulting from new highways and railways, and predictive models of impacts on landscapes and distant indigenous populations.

Dr. Rodrigo A. A. Nóbrega holds a degree in Cartographic Engineering from UNESP (1996), and a Master’s and PhD in Transportation Engineering specializing in Remote Sensing and GIS from the Polytechnic School of USP (2007) in Brazil. He completed his Postdoctoral studies at the Geosystems Research Institute – Mississippi State University (2010). With 28 years of experience in GIS, Dr. Nobrega’s research focuses on geographic intelligence for transportation planning. He is currently an Associate Professor at the Department of Cartography, Institute of Geosciences at Federal University of Minas Gerais (UFMG).