PATH

A Comparison Of Traffic Models: Part 1, Framework

Lo, Hong K.
Lin, Wei-hua
Lawrence, C.
Chang, Elbert
Tsao, Jacob
1996

This report defines a framework for comparing dynamic traffic models. It emphasizes four dimensions: functionality, traffic dynamics, route choice dy namics, and overall network performance. The first dimension compares the models through a check-list of model functions. Regarding the last three comparison dimensions, a total of five networks and twelve scenarios are defined. These test scenarios are designed to accentuate model properties and differences. Also included in the report are a list of performance measures for comparison purpose, and a discussion of the interpretation of...

A Comparison Of Traffic Models: Part 1, Framework

Lo, Hong K.
Lin, Wei-hua
Liao, Lawrence C.
Chang, Elbert
Tsao, Jacob
1996

This report defines a framework for comparing dynamic traffic models. It emphasizes four dimensions: functionality, traffic dynamics, route choice dy namics, and overall network performance. The first dimension compares the models through a check-list of model functions. Regarding the last three comparison dimensions, a total of five networks and twelve scenarios are defined. These test scenarios are designed to accentuate model properties and differences. Also included in the report are a list of performance measures for comparison purpose, and a discussion of the interpretation of...

Real-time Estimation of a Markov Process Over a Noisy Digital Communication Channel

Xu, Qing
Sengupta, Raja
2005

We study the real-time estimation of a Markov process over a memoryless noisy digital communication channel. The goal of system design is to minimize the mean squared estimation error. We first show the optimal encoder and decoder can be memoryless in terms of the source symbols. We then prove the optimal encoder separates the real space with hyperplanes. In the case of the binary symmetric channel and scalar source, the optimal encoder can be a threshold. A recursive algorithm is given to jointly find a locally optimal encoder and decoder for the binary symmetric channel. For a memoryless...

Planits: The Case-based Reasoner As A Planning Tool For Intelligent Transportation Systems

Khattak, Asad
Kanafani, Adib
1995

This paper develops a data synthesis methodology in PLANiTS (Planning and Analysis Integration for Intelligent Transportation systems) using case- based reasoning. The reasoner contains mechanisms for matching, ranking and analyzing past cases in relation to current cases. The current cases consist of transportation improvement actions, performance measures and environments defined in terms of spatial, temporal and user dimensions. PLANiTS users can apply increasing levels of stringency to match cases. The authors also discuss issues related to computer implementation and the limitations...

Vehicle Lateral Control Under Fault in Front and/or Rear Sensors: Final Report

Lu, Guang
Huang, Jihua
Tomizuka, Masayoshi
2004

This report presents the research results of Task Order 4204(TO4204), "Vehicle Lateral Control under Fault in Front and/or Rear Sensors". This project is a continuing effort of the Partners for Advanced Transit and Highways (PATH) on the research of passenger vehicles for Automated Highway Systems (AHS).

Bay Area Simulation and Ramp Metering Study - Year 2 Report

Gardes, Yonnel
Kim, Amy
May, Dolf
2003

As part of the California PATH program, the Paramics microscopic traffic simulation model was evaluated through a pilot application to the I-680 freeway corridor, one of the most highly congested facilities in the San Francisco Bay Area. The main objective of the project was to test the capability of the model to serve as a tool for evaluating alternative transportation planning and traffic management scenarios. HOV lanes were investigated first on a "simple" network, and later on the existing I-680 corridor. An Application Programming Interface (API) "plugin" designed by Quadstone, which...

The Potential of Using Transit Infrastructure for Air Freight Movement: A Case Study in the Bay Area

Wang, Rui
Lu, Xiao-Yun
Sivakumaran, Karthik
2010

This report examines the impact and feasibility of using urban railway system for freight movement. In particular, using the Bay Area Rapid Transit (BART) system for FedEx Express air cargo movement is analyzed as a case study. Based on the framework constructed in the study of last phase, social impact (externalities), reliability, and infrastructure feasibility are considered. The social cost related to emission, energy consumption/efficiency, impact on road traffic and land use is considered. The reliability issue is examined from two aspects: transportation delay, and emergency...

Investigation of Elderly Driver Safety and Comfort: In-Vehicle Intersection “Gap Acceptance Advisor” and Identifying Older Driver Needs

Bougler, Benedicte
Cody, Delphine
Geyer, Judy
Horne, Jedidiah H.
Misener, James A.
Nowakowski, Christopher
Rodier, Caroline J., PhD
Ragland, David, PhD
Shaheen, Susan A., PhD
Caguimbaga, Joy
Daniels, Bevin
Hamel, Kathryn, PhD
2005

Our work in Toyota GapAdvise is comprised of two interrelated elements: identify driving task challenges, and a pilot study on one particular class of decision support system, an intersection gap advisor. From these elements, we have recommended countermeasures and potential design guidelines for the elderly driving population in the United States.We performed our work in the following sequence of technical tasks, each corresponding to a section heading in this final report:Determine Extent of Problem (Task 1). From crash databases and demographic data, we have determined the projected...

Adaptive Control for Conventional Modes of Operation of MEMS Gyroscopes

Park, Park
Horowitz, Roberto
Tan, Chin-Woo
2002

This report presents adaptive control algorithms for conventional modes of operation of MEMS z-axis gyroscopes. In an open-loop mode, an off-line self-calibration scheme is proposed for estimating fabrication imperfections and enhancing the performance of a gyroscope operating in open-loop mode. This scheme can be implemented during the initial calibration stage when the gyroscope is turned on, or at regular calibration sessions, which may be performed periodically. An adaptive add-on control scheme is also proposed for a closed-loop mode of operation. This scheme is realized by adding an...

Vehicle Longitudinal Control Using Discrete Markers

Love, David W.
Tomizuka, Masayoshi
1994

In this report, a hybrid observer is proposed as a method of estimating position and velocity of a vehicle when the primary output is a series of discrete magnetic markers placed along a roadway. For the preliminary studies, the vehicle was modeled as a pure inertial system with acceleration input. Two methods of determining the time "tk" at which the "k-th" marker is passed are discussed, and simulations using both methods are shown. Compensation for errors arising due to inaccurate measurement of this time is proposed and validated. A Proportional- Integral-Derivative (PID) controller...