PATH

Object Management Systems

Gollu, Aleks Ohannes
1995

This thesis describes a new approach for developing large-scale object- oriented software systems, called Object Management Systems (OMS). The OMS development methodology consists of four stages: Domain Customization, System Architecture, Application Development, and System Test. The methodology is demonstrated by implementing the SmartAHS simulation framework, a Customized Object Model. SmartAHS is used to capture different Automated Highway System (AHS) designs and benchmark scenarios and to generate performance metrics through micro-simulation of the designs. The California PATH Program...

A Handbook For Inter-vehicle Spacing In Vehicle Following (includes Disk)

Sun, Y.
Ioannou, P.
1995

In this paper, a general worst case stopping scenario for vehicle following is used to develop algorithms for generating the minimum safety spacing (MSS) for collision-free vehicle following. These algorithms are used to study the effects of vehicle characteristics and other parameters on the value of the MSS. Furthermore, a case is considered where the choice of a smaller value of inter-vehicle separation leads to a rear-end collision. The effects of the various parameters on the severity of collision by using a proposed algorithm are studied. The results and algorithms developed in this...

A Staggered-diamond Design For Automated/manual - Hov Highway-to-highway Interchange

Tsao, Jacob
1995

This paper proposes a staggered-diamond design for automated connector ramps for an Automated Highway System (AHS). After describing the main features of this design, the paper discusses the constraints on AHS operational design imposed by the requirement for continuous automated highway-to-highway driving. The constraints on AHS evolution due to the same requirement are then discussed.

Cooperative Intersection Collision Avoidance System (CICAS): Signalized Left Turn Assist and Traffic Signal Adaptation

Misener, Jim
Barnes, M.
Chan, Ching-Yao
Cody, Delphine
Dickey, Susan
Goodsell, R.
Gordon, Tim
Kim, Zu Whan
Kuhn, Tom
Lian, Thang
Nelson, David
Nowakowski, Christopher
Nubukawa, K.
Sharafsaleh, Ashkan
Shladover, Steven
Spring, John
VanderWerf, Joel
Zhang, Wei-Bin
Zhang, Liping
Zhou, Kun
2010

The Cooperative Intersection Collision Avoidance (CICAS) program is a multi-year, cooperative research program including federal, state, academic, and industry partners. The goal of the research program is to use ITS technologies to address the problem of intersection crashes. The program is funded through an 80/20 cost share, typically split between the U.S. Department of Transportation (D.O.T.) and a local state D.O.T. The program began in 2003, and has been divided into three functional segments based on crash type. The largest programmatic segment is CICAS-V (Violation) which is led by...

Conditions for Safe Deceleration of Strings of Vehicles

Lygeros, John
Lynch, Nancy
2000

A simple model for a string of vehicles is constructed. The model explicitly accounts for the possibility of repeated collisions between the vehicles in the string. Based on the model a notion of safety is formulated for the string. Necessary and sufficient conditions are presented that specify when a string of vehicles is safe while performing a simple emergency deceleration maneuver where all vehicles start decelerating at a fixed rate after some delay. The conditions are interpreted in terms of their implications for the safety of platoons of vehicles.

California System Architecture Study: Architecture for Action: A Strategy for Facilitating Near-term Deployment

Horan, Thomas A.
Glazer, Lawernce Jesse
Hoene, Christopher
Hall, Randolph
Intihar, Christopher
Ice, Ronald
1999

Intelligent Transportation Systems (ITS), ushered in by ISTEA in 1991 and advanced under TEA-21 in 1998, fundamentally alter transportation planning and implementation in the United States. ITS shifts emphasis away from new construction and capacity to more efficient management of existing systems, in the process requiring increased coordination and integration of standards, systems, and policies. The National ITS Architecture provides a framework for integration, but leaves the majority of the implementation decisions to the state, regional, and local levels. California is well-positioned...

Enhancements To A Simulation Framework For Analyzing Urban Traffic Networks With Atis/atms

Jayakrishnan, R.
Rathi, U.
Rindt, C.
Vaideeshwaran, G.
1996

This report focuses on the DYNASMART simulation program presents a model that is capable of simulating large urban networks under various Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS) strategies. It includes modules for driver responses to information and for capturing the dynamics of the network paths. The research also included the simulation study of a network in Orange County, California, where the benefits from candidate ATIS and ATMS strategies were evaluated. The DYNASMART model has evolved into a flexible tool that can be applied to...

Spatial and Temporal Utility Modeling to Increase Transit Ridership

Church, Richard L.
Noronha, Val
Lei, Ting
Corrigan, Wils
Burbidge, Shaunna
Marston, Jim
2005

The objective of this research project was to develop a better understanding of the possible alternatives that a large employment center, like the University of California at Santa Barbara, can adopt in order to better utilize transit, mitigate traffic, and reduce demand for on-site parking. Although this project was oriented to the UCSB campus, the techniques and approaches developed in this project were designed to be equally applicable elsewhere. There were three major elements of this project: 1) develop an understanding of commuting employees through the use of a survey, 2) identify...

Impacts Of Smart Cards On Transit Operators: Evaluation Of I-110 Corridor Smart Card Demonstration Project

Chira-Chavala, Ted
Coifman, Benjamin
1996

This report presents the evaluation of the first transit smart card demonstration in California. The study assesses the cost and benefit implications of the smart card system to transit agencies. Two types of smart cards were used: radio frequency (RF) proximity and contact. The assessment of the cost and productivity impacts, as well as the perceptions of transit personnel, were accomplished through personnel interviews and independent onboard observations.

Travel Times on Changeable Message Signs: Pilot Project

Chen, Chao
2004

We describe a system to display real time travel times on Changeable Message Signs (CMS) in California. CMS's show dynamic information and allow the Traffic Management Center (TMC) to communicate to drivers information about traffic diversion, incidents, and delays. This type of service is deployed in other parts of the country and world and has been shown to be useful. For this project, we implemented a system that uses existing algorithms for travel time estimation and prediction.