PATH

Communications And Positioning Systems In The Motor Carrier Industry

Scapinakis, Dimitris A.
Garrison, William L.
1991

Until recently, truck drivers and their dispatchers have relied on public telephones and voice radio systems to communicate with each other. Today, however, vendors are beginning to offer new technologies for determining the positions of trucks and communications to and from trucks. Eighteen systems and their implications for the industry and intelligent vehicle highway systems (IVHS) activities are reviewed in this paper. Some of the newer communications and/or positioning systems are in the proposal stage. Others are available with not yet fully developed capability or only in limited...

Assessing Benefits of Coordination on Safety in Automated Highway Systems

Choi, Woosuk
Swaroop, Darbha
2001

In this report, we present a methodology for assessing the benefits of different vehicle coordination strategies on the safety of a platoon during emergency braking. One can say that a coordinated braking strategy B is more beneficial than a strategy, if strategy B leads to a larger reduction in the probability of a collision, the expected number of collisions, and the expected relative velocity at impact as compared to strategy .We consider an emergency braking scenario, in which the lead vehicle brakes at its maximum capability and the following vehicles brake while obeying a vehicle...

Deployment Path Analysis for Cooperative ITS Systems

Shladover, Steven E.
2009

Although the performance advantages of cooperative ITS systems are generally appreciated, the deployment challenges that they pose represent a significant impediment. This report begins with a summary of the types of deployment challenges faced by cooperative information systems and cooperative vehicle-highway automation systems (CVHAS), both of which require coordination of deployment of vehicle and infrastructure-based elements. The institutional challenges are discussed first, followed by the technological challenges. In each case, current progress in overcoming these challenges is...

Advanced Public Transportation Sytems; A Taxonomy, Commercial Availability And Deployment, Phase II

Khattak, Asad
Et. al.
1997

This study explores the development and availability of Advanced Public Transportation Systems (APTS) technologies. The study refines a taxonomy of transit technologies and uses it to explore the availability of new technologies and their impacts in transit agencies. THe taxonomy is based on defining the features, functions and performance characteristics of transit technologies. Based on the taxonomy, three surveys of technology suppliers were conducted. Questions were related to technology features, functions, performance, implementation, and impacts.0

Modeling And Simulation Of The Automated Highway System

Eskafi, Farokh H.
1996

This report presents the hierarchical structure for the control design of an Automated Highway System (AHS). This control hierarchy has four layers: network, link, coordination, and regulation. It is used to model different AHS proposals. Control layers and the internal structure of each layer and the interfaces between then are described. Three basic maneuvers are described: join, split, and change lane. The SmartPath simulation tools are described to enable simulating AHS scenarios. The advantages of SmartPath include providing a graphical interface, providing microsimulation, and also...

Roadway and Work Crew Conspicuity

Barton, Joseph E.
Misener, James A.
2000

Abstract. The work reported here quantitatively addresses the measurement of conspicuity of highway features and Caltrans work zones -- from the perspective of driver detection. The method focused on acquiring and operating on a computational visual signature analysis tool, but it evolved into evaluating the detection process, then selecting and exercising human perception-acquisition models suitable for development into a tool for conspicuity measurement. A composite, quantitative model of conspicuity was developed, verified, and applied to some sample roadside scenes. Key Words....

Lane Assist Systems for Bus Rapid Transit, Volume II: Needs and Requirements

Zhang, Wei-Bin
Shladover, Steven
Cooper, Douglas
Chang, Joanne
Miller, Mark
Chan, Ching-Yao
Bu, Fanping
2007

This report defines the transit service needs that can be met by use of lane assistance systems and the requirements that these systems must meet in order to be useful and safe. The work is based on review of the existing literature and research on the subject of lane assistance, combined with case studies of several transit properties that could potentially benefit from use of lane assist systems. The project team has conducted workshops involving participation by a broad mix of people representing the transit properties in order to learn about the needs that they perceive, as well as...

Micro-simulation Modeling Approach to Applications of On-line Simulation and Data Fusion

Chu, Lianyu
Recker, Will
2004

This report summarizes research work conducted under TO4143 at the California PATH ATMS Center at the University of California, Irvine. This project has two tasks: Functionality enhancements of the PARAMICS simulation model through API programming for the on-line simulation application; On-line data fusion algorithm for a better section travel time estimation based on point detector data and probe vehicle data. In order to conduct these two tasks, we complete the following two related studies, which are the basis of the two tasks of this project: Development of the capability-enhanced...

Fault Tree Analysis Of An Automated Freeway With Vehicle-borne Intelligence

Hitchcock, Anthony
2004

This report summarizes research work conducted under TO4143 at the California PATH ATMS Center at the University of California, Irvine. This project has two tasks: Functionality enhancements of the PARAMICS simulation model through API programming for the on-line simulation application; On-line data fusion algorithm for a better section travel time estimation based on point detector data and probe vehicle data. In order to conduct these two tasks, we complete the following two related studies, which are the basis of the two tasks of this project: Development of the capability-enhanced...

Development and Evaluation of Selected Mobility Applications for VII: Concept of Operations

Shladover, Steven E.
Lu, Xiao-Yun
Cody, Delphine
2009

This report describes the concept of operations for the three mobility applications that PATH is developing and evaluating under the sponsorship of the FHWA Exploratory Advanced Research Program. These applications are intended to use DSRC wireless communications among vehicles and between vehicles and the roadway infrastructure to improve mobility on limited-access highways. The first application combines ramp metering with variable speed limits to enhance control of traffic so that traffic flow breakdowns can be deferred or avoided at bottleneck locations. The second application uses...