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Open Access Publications from the University of California


California PATH is a unique research organization. It focuses on solving California's and the nation's transportation problems by conducting relevant and high-quality research that advances the state of the art. The research is performed by a statewide group of faculty, graduate students, and research staff of diverse backgrounds and expertise working closely together. At the same time, PATH produces the next generation of leaders in academia and the transportation profession. PATH's ongoing research directly addresses the mobility, reliability, and safety goals of our Caltrans (California Department of Transportation) partners and will place major emphasis on field testing of the most promising strategies for traffic control, traveler information, intersection safety, transit, and other mobility options.

Alexander Skabardonis, Adjunct Professor of Civil and Environmental Engineering and Research Engineer at the Institute of Transportation Studies, is PATH's director.

California Partners for Advanced Transportation Technology

There are 1043 publications in this collection, published between 1977 and 2024.
Working Papers (257)

Bus Lanes/Bus Rapid Transit Systems on Highways: Review of the Literature

This report presents the findings of a study of commercial motor vehicle inspection and screening station practices with a focus on the use of various technologies to help address problems related to safety, security, roadway infrastructure, and air quality. A review of industry literature identified the various types of inspection and screening practices that have been and are being implemented including weight and size management, on-board equipment checking, driver-related violations and cargo monitoring, credential checking, and exhaust emissions monitoring. The review also identified technologies that have been employed as part of these practices as well as an assessment of their performance. The research also involved the use of a survey of State and Provincial Departments of Transportation in North America that have implemented specific practices. Survey findings indicate that to a certain degree a more integrated and multi-practice approach is being taken; a wide array of technologies is in use; and, technology evaluations show they have generally performed well.

Organizing For Its: Computer Integrated Transportation Phase 2: Results For Commercial Vehicle Operators

This paper extends previous research on Computer Integrated Transportation (CIT) to commercial vehicle operations (CVO), specifically to examine how government can work with trucking companies within a CIT framework. The research entailed a review of how government currently interacts with trucking companies, interviews with trucking terminal managers, and case-studies on terminal operations at five of the nation's largest motor carriers. Opportunities are identified in the area of unifying interaction between government and industry and in the area of in- vehicle devices for automated record keeping.

Investigation of Vehicles as Probes Using Global Positioning System and Cellular Phone Tracking: Field Operational Test

This paper reports on the first phase of the location technology evaluation for probe vehicles. Two technologies were evaluated, Global Positioning Systems (GPS) and the cellular phone tracking technology developed by US Wireless. Although GPS has shown great potential for vehicle probes, much of the previous research is theoretical in nature. Very little work has been done in the areas of experimental research, implementation or deployment. Most of the field tests were anecdotal; a systematic approach is highly desired to develop a vehicle probe system that is reliable and efficient for traffic management. If GPS is widely deployed in cellular phones, as GTE in 1998 predicted would happen, GPS technology will become even more attractive and realistic for vehicle probe activities. A custom software package was developed as part of this project in order to conduct the technology evaluation. The software, the Travel Information Probe System (TIPS) maps positions of probes of arbitrary accuracy to an embedded Geographical Information System (GIS) in order to determine the path the probe took. Once the path has been determined, the software calculates the travel time for each road segment traversed. The preliminary analysis of two Bay Area counties showed that accurate location technologies are capable of producing travel time information for nearly all roads. A technology with 20-meter accuracy can produce data for 99.2% of road segments and 98.9% of the freeway segments in the two counties studied.

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Research Reports (786)

Development of BRT Architecture: A System Engineering Approach

This report discusses the development of system architecture for Intelligent Transportation Systems (ITS) applications for Bus Rapid Transit (BRT) systems. In the course of the development of system architecture, it is critical to take a system engineering approach in the development of BRT architecture to assess BRT service needs (or features), the functional realization of these service needs and the means of technological implementation. Motivated by the National ITS architecture, the BRT architecture has a hierarchy of three layers: application, physical, and logical. The application layer consists of the BRT service needs or features. For the physical layer, we first discuss a functional analysis that begins with the identification of system operational features, followed by an identification of the functions that are needed to achieve these operational features. We create a physical architecture modeled around each of the BRT features. In the final step, the logical architecture is traced or mapped from the physical architecture in such a way that the physical layer will implement the processes identified in the logical architecture and assign them to subsystems, and the data flows that originate from one subsystem and end at another are grouped together into architecture flows.

Longitudinal Control Development For Ivhs Fully Automated And Semi-automated Systems - Phase 1

This report addresses some of the important longitudinal vehicle modeling and control issues of Advanced Vehicle Control Systems (AVCS) such as brake dynamic model development and validation, decentralized longitudinal control algorithms which guarantee the stability of the entire platoon and fault detection and isolation in the longitudinal vehicle dynamics of controlled vehicles.

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