Breakout #21

Breakout Session #21

Traffic Flow Of Connected Automated Vehicles

Wednesday, July 20, 2016

Room: Union Square 5 & 6


  • Xiaopeng (Shaw) Li, University of South Florida
  • Haizhong Wang, Oregon State University
  • Sue Ahn, University of Wisconsin-Madison
  • Robert L. Bertini, Cal Poly, San Luis Obispo
  • Mark Brackstone, Transport Simulation Systems
  • Danjue Chen, University of Wisconsin-Madison
  • Samer Hamdar, George Washington University
  • Steve Mattingly, University of Texas, Arlington
  • Menendez Monica, Swiss Federal Institute of Technology
  • Gabor Orosz, University of Michigan - Ann Arbor
  • Alireza Talebpour, Texas A&M University


Description: This breakout session provides an opportunity to bring together the cyber-physical/communications, vehicle control and traffic flow communities to better understand the fundamental characteristics of traffic flow with varying levels of automation and identify research needs for developing models to assess the safety, environment and mobility implications of connected automated vehicles (CAV). This breakout session will focus on discussion of innovative modeling of CAV traffic flow, CAV based traffic control and management methods, cyber-physical communication frameworks, and related technologies translatable to traffic flow modeling.

Through this breakout session, the group will discuss these themes and potential simulation tools/approaches, data needs, availability and sources (especially those publicly available), key opportunities for collaboration across research communities and major challenges in each area. This breakout session will include broad representations from academia, governments, and industry.

This breakout session will develop a working group for this collaborative effort, identify research needs and generate research problem statements. The planned outputs for the session include keynote and session presentations, discussion group notes, a core working interest group to keep the momentum going beyond the symposium.


1. Keynote presentations (one hour)

Speaker: Hani Mahmassani, Northwestern University
Title: Autonomous vehicles and traffic physics: framing the questions
Abstract: TBD

Bio: Dr. Hani S. Mahmassani holds the William A. Patterson Distinguished Chair in Transportation at Northwestern University, where he is the Director of the Northwestern University Transportation Center. He has over 30 years of professional, academic and research experience in the areas of intelligent transportation systems, freight and logistics systems, multimodal systems modeling and optimization, pedestrian and crowd dynamics and management, traffic science, demand forecasting and travel behavior, information technology and mobile social networking, and real-time operation of transportation and distribution systems. He has served as principal investigator on over 140 funded research projects sponsored by international, national, state, and metropolitan agencies and private industry. He is past editor-in-chief and current associate editor of Transportation Science, senior editor of IEEE Transactions on Intelligent Transportation Systems, and founding associate editor of Transportation Research C: Emerging Technologies. He has served in an advisory capacity to various institutes and programs, and has performed several program assessments of leading international research institutes and corporate R&D departments. He is emeritus member of Transportation Research Board committees on travel behavior analysis, telecommunications and travel behavior, and network modeling. Mahmassani received his PhD from the Massachusetts Institute of Technology in transportation systems and his MS in transportation engineering from Purdue University.


Speaker: Pravin Varaiya (joint work with J.Lioris, F. Yildiz, R. Pedarsani, D. Farias, A. Kurzhanski, A. Askari), University of California, Berkeley
Title: Autonomous vehicles and traffic physics: framing the questions
Abstract: Intersections are the bottlenecks of the urban road system because an intersection’s capacity is only a fraction of the vehicle flows that the roads connecting to the intersection can carry. The saturation flow rate, and hence the intersection’s capacity, can be doubled if vehicles can cross intersections in platoons rather than one by one as they do today. Platoon formation is enabled by connected vehicle technology. Doubling the saturation flow rate has dramatic mobility benefits: the throughput of the road system can be doubled, or vehicle queues and delay at intersections can be halved. These predictions draw on an analysis of a queuing model of a signalized network with fixed time control and they are validated in a simulation of a small urban network with 16 intersections and 73 links.

Bio: Pravin Varaiya is a Professor of the Graduate School in the Department of Electrical Eng ineering and Computer Sciences at the University of California, Berkeley. From 1994 to 1997 he was Director of the California PATH program, a multi-university research program dedicated to the solution of California’s transportation problems. He has taught at MIT and the Federal University of Rio de Janeiro. He has been a Visiting Professor at the Institute for Advanced Study at the Hong Kong University of Science and Technology since 2010. His current research is devoted to electric energy systems and transportation networks.

Varaiya has held a Guggenheim Fellowship and a Miller Research Professorship. He has received Honorary Doctorates from L’Institut National Polytechnique de Toulouse, L’Institut National Polytechnique de Grenoble and the Technical University of Crete. He received the Richard E. Bellman Control Heritage Award, the Field Medal and Bode Lecture Prize of the IEEE Control Systems Society, and the Outstanding Researcher Award from the IEEE Intelligent Transportation Systems Society. He is a Fellow of IEEE, a member of the National Academy of Engineering, and a Fellow of the American Academy of Arts and Sciences.


2. Session presentations (one hour)

Session Presentation I

Speaker: Osman Altan, Federal Highway Administration
Title: Research in Connected Automation Applications to Improve Mobility
Abstract: Automation can significantly enhance the operation of the highway transportation system by improving mobility, safety, and environmental performance. Some partial automation (Level 1) systems that use vehicle-vehicle and vehicle-infrastructure communication offer opportunities to reduce traffic congestion. These applications include cooperative adaptive cruise control (CACC), speed harmonization, and cooperative lane change-merge. Ongoing research sponsored by the Federal Highway Administration is supporting the development and testing of these emerging applications. Some simulation studies have suggested that CACC might effectively double the capacity of urban freeways, but additional studies are continuing. Future deployment of bundled applications of CACC, speed harmonization, and cooperative merging on managed lanes may provide opportunities to gain significant performance improvements for travelers.

Bio: Dr. Altan is a Research Transportation Specialist with the Federal Highway Administration. He received his B.Sc. degree in Electrical Engineering from METU in Ankara, Turkey, and M.Sc. and Ph.D. degrees in Electrical and Computer Engineering from the University of California in Berkeley. He worked at Space Sciences Laboratory on experimental satellite systems launched by NASA for data collection. After briefly teaching at Universities, he spent most of his career at General Motors Research Laboratories, specializing on active safety systems, automated systems, and connected systems. He has over 15 patents on related subjects and contributed to company’s commercial products on safety systems. Later, he joined US DOT’s VOLPE Center in Cambridge, Massachusetts working on performance requirements of safety systems based on connectivity and automated vehicle projects. Currently he is with FHWA’s Turner Fairbank Highway Research Center managing several projects related to connected automation.


Session Presentation II

Speaker: Simeon Calvert, TNO
Title: Knowledge gaps in relation to the impacts of automated driving in mixed traffic
Abstract: TrafficQuest and TNO recently performed an exercise to review the current knowledge gaps in traffic flow theory and modelling for consideration of the impacts of automated vehicles (AVs) in mixed traffic. Various conflicts between conventional and AVs were considered in a case study for a busy weaving section. This resulted in a number of key traffic situations for which current practice does not hold answers and also resulted in a list of research questions that need to be addressed. These challenges are relevant for national road authorities, traffic flow modelers and also the automotive industry, to adequately address them in the transition to higher AV-levels. An important challenge lies in the prediction and forecasting of unknown behavior for which very little to no ground truths are available.

Bio: Simeon Calvert was born in Edinburgh, Scotland, and has since lived for the majority of life in The Netherlands. Shortly after graduating from Delft University of Technology, Simeon joined the research institute TNO, The Netherlands Organization for Applied Scientific Research, as a research scientist. His work at TNO involves applied scientific research on topics relating to traffic flow theory, traffic flow modelling, traffic management, network analysis and the impact of automated and cooperative driving. During this time, Simeon completed his PhD at Delft University of Technology, while continuing to work at TNO. This research focused on the analysis and modelling of stochasticity in traffic flow to improve evaluation and implementation of traffic management on high level roads and was completed in May 2016. Simeon maintains a broad interest in a vast number of traffic flow related topics and has a particular interest in the impact of automated and cooperative driving towards the future, as well as traffic management and the analysis of traffic flows, in which he is involved in a number of leading research projects both for the European Commission as for national governments.

Session Presentation III

Speaker: Jan-Niklas Meier, CAMP
Title: CACC – V2X Solutions to ACC Challenges
Abstract: Cooperative Adaptive Cruise Control is an extension to conventional ACC that aims to enhance system performance through the use of Vehicle-to-Vehicle and Infrastructure-to-Vehicle communication. With CACC, strings of equipped vehicles form that travel through traffic fast and adapt to surrounding conditions intelligently.
Building upon the existing ACC and the about-to-be-deployed V2X communication, CACC might be one of the first widely introduced connected automation systems. While CACC is a Level 1 automation system, it is anticipated that the findings can be applied to longitudinal control of connected automation systems in general.
A real-world implementation of CACC in vehicles of different makes and models poses challenges such as different OEM design choices and vehicle performance that need to be understood and considered. The CAMP CACC Small-Scale Test project is studying these challenges through simulation and vehicle testing.

Bio: Currently, he is leading the CACC Small-Scale Test project at the CAMP V2I Consortium consisting of ten light vehicle and one heavy duty truck manufacturer. The project aims to implement and study Cooperative Adaptive Cruise Control on vehicles of different makes and models.

Jan Niklas Meier

3. Panel Discussion Session (one hour)
The above five speakers will be the panelists for this session. This session may start with a few selected questions of our common interests and then it is open to any questions or comments from the audience. Questions related to the presentations will be addressed during this panel session as well. Notes will be taken in preparation for a session report.

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