PATH

A Simple Time Sequential Procedure for Predicting Freeway Incident Duration

Khattak, Asad J.
Schofer, Joseph L.
Wang, Mu-han
1994

The objective of this study is to develop a methodology for incident duration prediction. The authors first developed an understanding of factors that influence incident duration. A series of truncated regression models is used to predict incident duration. The models account for the fact that incident information at a Traffic Operations Center is acquired over the life of the incident. The implications of this simple methodology for incident duration prediction are discussed.

A Planning Methodology for Intelligent Urban Transportation Systems

Kanafani, Adib
Khattak, Asad
Crotty, Melanie
Dahlgren, Joy
1992

This report deals with an introduction to the control aspect of platoon maneuvers in Automated Highway Systems. The different platoon maneuvers include lane changes, merge procedures and split procedures. The first part of the report consists of a review of the existing literature in this area. The survey is split up into the quasi-synchronous and vehicle follower controller methods of approach to the problem. The subsequent sections deal with the mathematical description of the problem with two representations of the system under study, varying only in level of model complexity. The...

A Probabilistic Model and a Software Tool For AVCS Longitudinal Collision/safety Analysis

Tsao, H. S. Jacob
Hall, Randolph W.
1993

This paper develops a probabilistic model and a software tool for analyzing longitudinal collision/safety between two automated vehicles. The input parameters are the length of the gap between the two vehicles, the common speed prior to failure, the reaction delay of the following vehicle and a bivariate joint distribution of the deceleration rates of the two vehicles. The output includes the probability of a collision and also the probability distribution of the relative speed at collision time. The model is used to compare the safety consequences associated with the platooning and "free-...

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 Fuzzy Rule-Based Controller for Automotive Vehicle Guidance

Hessburg, Thomas
Tomizuka, Masayoshi
1991

A fuzzy rule-based controller is applied to lateral guidance of a vehicle for an automated highway system. The fuzzy rules, based on human drivers' experiences, are developed to track the center of a lane in the presence of external disturbances and over a range of vehicle operating conditions.

A Functional Architecture for Automated Highway Traffic Planning

Tsao, H. S. Jacob
1994

This report defines an architecture for Automated Highway System (AHS) capacity-optimizing traffic planning functions. It identifies major traffic planning functions useful for optimizing the capacity of one or more major AHS operating scenarios and organizes them in a robust architecture that is modular, hierarchical, complete, expandable and integratable.

A First Example Specification of an Automated Freeway

Hitchcock, Anthony
1991

This paper presents a specification for an automated freeway in a fully formal manner. A series of safety analyses have been carried out on the specification. The objective of the program is to derive a technique of safety analysis for such systems. Readers are advised to consult " Methods for Analysis of IVHS Safety: Final Report of PATH MOU 19" by the author for background information to this report.

A Dynamic Visualization Environment for The Design and Evaluation Of Automatic Vehicle Control Systems

Xu, Z.
1995

This document presents Dynamic Visualization, a project associated with the California PATH Program. The objective of the project is to develop a software which can animate automated highways, visualize the dynamics of automatic vehicles, and help the design and evaluation of automatic vehicle systems. This report summarizes the accomplishments of the project, describes the functions of the developed software, and provides an explanation of how to use the software.

A Continuing Systems-Level Evaluation of Automated Urban Freeways: Year Three

Johnston, Robert A.
Ceerla, Raju
1993

The purpose of this study was to demonstrate the travel and emissions impacts of urban freeway automation scenarios and to compare these to travel demand reduction scenarios, such as travel pricing and land use intensification. The Sacramento regional travel demand model set was used and an alternatives analysis was conducted. Two protocols are used to operate the model set. Results are discussed, comparing the alternative scenarios, and methodological findings are discussed, comparing the results from the two protocols for operating the model set. Methodological findings present new ideas...

A Comparative Systems-Level Analysis: Automated Freeways, Hov Lanes, Transit Expansion, Pricing Policies and Land Use Intensification

Johnston, Robert
1997

The focus of this project was to examine the potential travel, emissions, and consumer benefits of advanced freeway automation and travel demand management measures. The Sacramento Regional Travel Demand model (SACMET 95) was used to simulate the travel effects of travel demand management measures in the Sacramento region for a twenty year time horizon. The scenarios examined included various combinations of automated freeways, new High Occupancy Vehicle (HOV) lanes, transit, land use intensification, and pricing policies.