PATH

Time Space Diagrams For Thirteen Shock Waves

Coifman, Benjamin
1997

This paper presents microscopic time-space diagrams for several shock waves over 100-200m distances. The primary focus of the paper is on presenting the data rather than analysis. The diagrams should be of general interest to researchers studying traffic congestion.

An Object-oriented Database for IVHS

Varaiya, Pravin
1998

The objective of this proposal was to develop a database that integrates various elements-traffic simulation packages, data sets, and computational tools. The difficulty in integration was felt to be the incompatibility of data structures, formats, and software.It was proposed to design, build and test a software environment with an open architecture that would facilitate a synergistic use of these software elements. The core of this environment was to be an object-oriented commercial database system that would be sufficiently general to support many software elements, and which would...

A Link-Based Variational Inequality Model for Dynamic Departure Time/Route Choice

Ran, Bin
Hall, Randolph
Boyce, David E.
1995

The dynamic user-optimal (DUO) departure time and route choice problem is to determine travelers’ best departure times and route choices at each instant of time. In a previous paper, we presented a route-based two-level optimal control model for the DUO departure time/route choice problem. However, this model is not appropriate for large scale transportation networks because some degree of route enumeration is necessary to solve the model. In this paper, we present a link-based variational inequality (VI) formulation for the DUO departure time/route choice problem so that route enumeration...

Summary of Observations on July 1993 Study Tour to Japan

Orne, Donald E.
Shladover, Steven E.
1993

The purpose of this report is to document some lessons learned during the July 3-16, 1993 tour of Japan and Intelligent Vehicles ’93 Symposium attendance by PATH Director Donald E. Orne and Deputy Director/AVCS Program Manager Steven E. Shladover.The tour was arranged by PATH through Japanese contacts to coincide with the Intelligent Vehicles ’93 conference. Most of the contacts were known to PATH either from introductions at various conferences or by visits to PATH offices.Special attention was given by Orne and Shladover to consider the extent to which interaction with government,...

Robust Computation of Optical Flow in a Multi-Scale Differential Framework

Weber, Joseph
Malik, Jitendra
1993

We have developed a new algorithm for computing optical flow in a differential framework. The image sequence is first convolved with a set of linear, separable spatiotemporal filters similar to those that have been used in other early vision problems such as texture and stereopsis. Our analysis of the measurement errors leads us to develop an algorithm based on a robust version of total least squares. Each optical flow vector computed has an associated reliability measure which can be used in subsequent processing. The performance of the algorithm on the data set used by Barron et al. (...

Travinfo Field Operational Test: Work Plan For The Target, Network, And Value Added Reseller ( V A R ) Customer Studies

Yim, Y. B.
Hall, Randoph
Skabardonis, Alex
Tam, Robert
Weissenberger, Stein
1997

This report contains detailed work plans for the following evaluation tasks associated with the TravInfo evaluation study. These include: the target, Value Added Reseller (VAR) customer studies, and the network performance evaluation. The target study focuses on a high impact Bay Area corridor to evaluate TravInfo impacts or benefits to Bay Area travelers. The network performance evaluation simulates the road conditions in that corridor to estimate TravInfo impacts at the aggregate level. The VAR customer study provides information on those consumers who actually purchase and use Advanced...

Custom Interface Builder Palettes For Advanced Driver Interface Rapid Prototyping

Moore, David W.
1993

This manual provides a brief introduction to four classes of software objects developed to help a user create and test interfaces using these objects in the Interface Builder application environment. The Knob, Dial, Alert Light, and Map object classes presented here represent the beginnings of a software library of virtual interface objects designed to support a rapid prototyping environment for advanced interfaces as described in "Rapid Prototyping of Advanced Driver Interface Systems."

Los Angeles Fot Spread Spectrum Radio Traffic Signal Interconnect Evaluation Task: Final Report On Full Deployment

Li, Victor O. K.
Sengodan, Senthil
Chan, Tat-keung Ken
Zhuge, Lei
1998

This report presents the results of an evaluation of project in which spread spectrum radio networks (SSRN) were used for traffic monitoring and control in the City of Los Angeles. The focus of SSRN is to reduce construction costs, construction time and future plant maintenance costs. A field operational test was conducted to test and evaluate the applicability of SSRN communications in traffic control.

Optimization Tools For Automated Vehicle Systems

Shiller, Zvi
1995

This work focuses on computing time-optimal maneuvers which might be used to develop strategies for emergency maneuvers and establishing the vehicle' s performance envelope. The problem of emergency maneuvers is addressed in the context of time optimal control. Time optimal trajectories are computed along specified paths for a nonlinear vehicle model, which considers both lateral and longitudinal motions.

A Method for Relating Type of Crash to Traffic Flow Characteristics on Urban Freeways

Golob, Thomas F.
Recker, Wilfred W.
2003

A method is developed to determine how crash characteristics are related to traffic flow conditions at the time of occurrence. Crashes are described in terms of the type and location of the collision, the number of vehicles involved, movements of these vehicles prior to collision, and severity. Traffic flow is characterized by central tendencies and variations of traffic flow and flow/occupancy for three different lanes at the time and place of the crash. The method involves nonlinear canonical correlation applied together with cluster analyses to identify traffic flow regimes with...