Cross-cutting Issues

The transportation system of the United States has had significant impacts on the nation’s development, both geographically and economically. Yet inefficiencies and inherent dangers of that system cost billions and perhaps trillions of dollars every year, as well as thousands of lost lives. Automated Electric Transportation (AET) is a solution which addresses and has the potential to resolve many of those issues, particularly in relation to human factors in driving, for future transportation. However, in developing this new transportation system, new challenges arise that must be addressed. Therefore, the purpose of this paper is to provide a brief overview of the concept of AET and emphasize its potential impacts on transportation safety and mobility. It also addresses specific challenges that this new transportation system will face as it moves through its development. The discussion of these challenges, including deployment/transition strategy, environmental hurdles, incident response, and future expansion provides a springboard for further research and development in Automated Electric Transportation.

Authors: Derek Freckleton, James Fishelson, Kevin Heaslip, P.E. Ph.D.

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Intelligent Transportation Systems (ITS) technology has been in development for several
decades; however, there are notable barriers to its widespread deployment. To advance ITS
beyond its current scope, research efforts in the 21st century will need to pursue an agenda that integrates social, political/legal, energy/environmental, and economic/technology realization factors in the technical design process. The Integrated Active Transportation System (IATS) project seeks to achieve this agenda towards creating a seamless transportation system by incorporating a broad interdisciplinary approach to the development of a long-term vision for transportation in the United States (U.S.). As part of this effort, researchers examined previous ITS projects; interviewed experts in the field; formed and consulted with a project steering committee; and conducted two expert scenario workshops to develop plausible futures and to understand their possible effects on the transportation system. Barriers and opportunities for implementing advanced seamless transportation systems were identified for the 20- and 40-year timeframes. The most significant barriers identified were funding, technology adoption and obsolescence, and social acceptance. Opportunities include natural disasters; climate change; and adaptable, integrated technology/infrastructure deployment within the transportation system. Equipped with this understanding, researchers are now developing a research roadmap for U.S. transportation systems that address both technical and non-technical factors to the realization of IATS in the future.

Authors: Susan Shaheen, Ph.D., Madonna Camel, Kunik Lee, Ph.D.

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Abu Dhabi Department of Transport (DoT) recently completed and ITS Strategy and Action
Plan that provides a roadmap for transportation management and technology projects, including development of a multi-modal transportation management center (TMC). The plan has received full Government support to move ahead with initial ITS and TMC development, emphasizing deployment of active traffic management, travel time information, and pre-trip traveler information systems along with a signature TMC that will incorporate freeway and public transport operations, and will be connected to existing local traffic control centers handling urban traffic control activities.

Authors: Glenn N. Havinoviski, PE, Salah Mohammed Al-Marzouqi, Ra'id Breiwish, Ph.D.

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

The concept of the car following theory, the manner in which two cars follow one another without passing, has been closely studied in the last decades. As applied to traffic engineering and safety research, many models were developed to best mimic the interaction between adjacent vehicles in a traffic stream. The car following theory also forms the process of the microscopic traffic simulation models which attempt to replicate driver behavior in a traffic stream. Though most existing applications are limited to historical traffic data, wide utilization of new data collection tools, such as Global Position System and Automatic Vehicle Identification technologies are expected to lead to rapid improvements in existing car following models. The large amount of real-time traffic data provides a possibility to better calibrate and validate car following models to better represent the traffic conditions. This study summarizes the commonly used car following models, and discusses the applications and limitations of each. Using current limitations, this study also discusses the future potential improvements of car following models with new technologies, such as the real-time traffic information provided by the intelligent transportation technologies.

Authors: Yiming He, Mashrur Chowdhury, Ph.D., Taufiquar Khan, Ph.D., Yan Zhou Ph.D.

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Automatic vehicle sensors provide link traffic flow data in a transportation network which is valuable information to address long-term traffic planning and short-term operational needs of the transportation agencies. However, these sensors and their deployment are expensive, leading to the strategic problem of the identification of the subset of links on which to install them to maximize the information on link flows using a limited number of sensors. The need to estimate flows on the maximum number of possible links based on the measurement of link flows on a subset of links that have sensors installed on them, leads to the network sensor location problem (NSLP). Mostly, the NSLP is either solved as a sub-problem of broader problems such as origin-destination (O-D) matrix estimation, or by focusing on long-term
planning considering static traffic conditions. Since, in an operational context, traffic conditions change with time and multiple paths are used as the traffic evolves, there is the need to consider the dynamic traffic conditions in the NSLP. In this study, we formulate the NSLP to capture the traffic dynamics using the dynamic link-path incidence matrix which indicates the time-dependent presence of flow on links. This problem is then solved over the horizon of interest to obtain the subset of links that provide maximum expected network-level observability through sensors installed on them. In each time interval, the dynamic link path incidence matrix is used to compute the “basis links,” that is, the subset of links that provide complete observability of the network. The set of basis links computed in each time interval is used to identify the subset of links to install sensors on by maximizing observability gain from the links while considering the maximum number of sensors available for installation. The approach is useful for deploying short- term operational/long-term planning and link-based applications in traffic networks.

Author: Sushant Sharma

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida