PATH

Freeway Analysis Manual: Parts 1 and 2

May, Dolf
Leiman, Lannon
2005

This Freeway Analysis Manual is intended for those who are responsible for understanding, analyzing, and evaluating the operations of freeways for planning, design, and operational improvements of such facilities. Freeway analysis requires a creative person, knowledgeable in freeway analysis fundamentals, having good traffic data, and selecting appropriate analytical tools.

Integrated Maneuvering Control Design And Experiments: Phase II

Hedrick, J. K.
Pantarotto, M.
Yoshioka, T.
Chen, Y.
Connolly, T.
Narendran, V. K.
1996

This report begins with an examination of autonomous lateral vehicle control. This is followed by a section on Cooperative Intelligent Cruise Control (CICC). The effect of communication delays on the control performance of vehicle platoons is then examined. The report concludes with a study of the three basic transition maneuvers in an Automated Highway System: join, split, and lane change.

Models Of Vehicular Collision: Development And Simulation With Emphasis On Safety IV: An Improved Algorithm For Detecting Contact Between Vehicles

O'Reilly, Oliver M.
Papadopoulos, Panayiotis
Lo, Gwo-jeng
Varadi, Peter C.
1998

This report describes a procedure for detecting the geometry of the contact interface between vehicles. This technique uses a better approximation of the vehicle's shape and also preserves the advantage of the ellipsoidal model. This new model for the low relative velocity vehicular collision is based on a box model for the outer surface of the vehicle and is referred to as BM.

Empirical Analysis of Traffic Breakdown Probability Distribution with Respect to Speed and Occupancy

Chow, Andy H.F.
Lu, Xiao-Yun
Qiu, Tony Z.
2009

From an operation viewpoint, traffic breakdown (from free-flow) was defined as when the average speed of traffic drops below a certain threshold. It is known that traffic breakdown is a stochastic phenomenon which can happen even when the traffic flow is below the capacity. The capacity has many definitions, such as that in HCM or the average of maximum daily flow. This study investigates the probability of breakdown at certain locations of freeway. The motivation is to find a practical capacity for each freeway section for active traffic control/operation purposes, which could be...

Smartpath Regulation Layer Implementation: A User's Guide

Carbaugh, Jason
Alvarez, Luis
Chen, Pin-yen
Horowitz, Roberto
1997

This report describes the implementation of the regulation layer maneuvers for the hierarchical architecture in SmartPath. The report contains information regarding the simulation of automated vehicle control laws in the SmartPath environment. It also provides an overview of the set of maneuvers currently implemented.

Issues In Fault Tolerant Control Of Vehicle Follower Systems

Hedrick, J. K.
Garg, V.
1994

The aim of this report is to study issues concerning fault detection and identification in vehicle follower control. The report discusses various potential fault modes among sensors, and actuators used in the vehicle following experiments in cars. It deals with issues of fault detection of sensors and actuators for vehicle following applications.

Alternative Traffic Signal Illumination

Cohn, Theodore E.
Greenhouse, Daniel
Knowles, Richard
1998

New technologies have enabled the production of traffic signals that have significant advantages over standard incandescent signals, including greater energy efficiency and lower maintenance costs. Before the new signals are installed in the field, it is important to assure that they as visible as the older signals. We have developed a quality index we term the usability factor (UF) which can be used to evaluate the visibility of a new device relative to that of a standard reference lamp. We have measured UF's of a variety of new types of lamps by means of heterochromatic flicker...

Extracting More Information from the Existing Freeway Traffic Monitoring Infrastructure

Coifman, Benjamin
2006

This report presents the results of TO 5302, Extracting More Information from the Existing Freeway Traffic Monitoring Infrastructure. This report represents significant advances in the PATH sponsored research into vehicle reidentification from conventional loop detectors, first by extending the methodology across major merge and diverge freeway sections. Second, it extends the methodology to single loop detectors. The report also extends the understanding of traffic phenomena impacting both traffic flow and the performance of the reidentification algorithms. It examines the impacts of lane...

Safety Assessment of Advanced Vehicle Control and Safety Systems (AVCSS): A Case Study

Chan, Ching-Yao
Zhang, Wei-Bin
El Koursi, El Miloudi
Lemaire, Etienne
2001

Advanced Vehicle Control and Safety Systems (AVCSS) involve several safety critical functionssuch as vehicle longitudinal and lateral control. It is required that the system be able to prevent ormitigate hazardous conditions. The system must be capable of tolerating failures and, whenfailures are no longer tolerable, be fail-safe. In order to verify the safety of a system, anassessment or evaluation methodology must be developed and implemented prior toimplementation of new technologies such that errors in the processes of specification, design,development, and integration can be revealed...

Development and Performance Evaluation of AVCSS Deployment Sequences to Advance from Today's Driving Environment to Full Automation

Shladover, Steven
VanderWerf, Joel
Miller, Mark A.
Kourjanskaia, Natalia
Krishnan, Hariharan
2001

This report presents the findings of its investigation into deployment sequences to better understand the paths that could be taken from today's driving environment to vehicle-highway automation. One of the most vexing problems has always been that of determining how to advance from the present-day manually-controlled vehicles to the future fully automated vehicles. Considerable research attention has been devoted to defining the architecture and operating protocols, as well as the technology, of automated highway systems. Rather less attention has been devoted to defining the steps by...