Roads/Highways

A Comparable Systems Analysis Of San Francisco's BART: Lessons For Automated Highway Systems

Hickman, Mark D.
1994

This study examines the lessons to be learned from the experience of the San Francisco Bay Area Rapid Transit (BART) system, particularly as applied to the growing research on automated highway systems (AHS). The first section of the report briefly motivates the analogy of BART by comparing some of the technical and non-technical performance factors surrounding both AHS and BART. Several pertinent technical and non- technical issues surrounding BART are described in more detail, emphasizing the decision-making that went in to BART's development, testing, and the beginning of revenue...

A Network Layer for Intelligent Vehicle Highway Systems

Eskafi, Farokh
Zandonadi, Marco
1999

The objective of this paper is to design the network layer of a communication stack to be used in Automated Highway Systems (AHS). The communication model we propose allows cars to form private subnets, the configuration of which can change dynamically. Each car be part of multiple subnets and can send broadcast, multicast and point-to-point messages to other vehicles (both on the same subnet and on others, through a routing mechanism). Each subnet is managed by a server: a car that is in charge of accepting/rejecting join requests and of keeping a consistent state within the subnet....

Freeway Performance Measurement System, PeMS v3, Phase 1: Final Report

Varaiya, Pravin
2001

PeMS is a freeway performance measurement system for all of California.  It processes 2 GB/day of 30-second loop detector data in real time to produce useful information. Managers at any time can have a uniform, and comprehensive assessment of freeway performance.  Traffic engineers can base their operational decisions on knowledge of the current state of the freeway network.  Planners can determine whether congestion bottlenecks can be alleviated by improving operations or by minor capital improvements.  Travelers can obtain the current shortest route...

Safety Aspects of Freeway Weaving Sections

Golob, Thomas F.
Recker, Wilfred W.
Alvarez, Veronica M.
2003

One source of vehicle conflict is the freeway weaving section, where a merge and diverge in close proximity require vehicles either entering or exiting the freeway to execute one or more lane changes. Using accident data for a portion of Southern California, we examined accidents that occurred on three types of weaving sections defined in traffic engineering: Type A, where every merging or diverging vehicle must execute one lane change, Type B, where either merging or diverging can be done without changing lanes, and Type C, where one maneuver requires at least two lane changes. We found...

A Machine Vision Based Surveillance System for California Roads

Malik, J.
Russell, S.
1995

In this report we address the problem of automation of heavy-duty vehicles. After a brief description of the dynamic model used in our design and simulations, we develop nonlinear controllers with adaptation, first for speed control and then for vehicle follower longitudinal control. We consider both autonomous operation as well as intervehicle communication, and evaluate the performance of our controllers in several different scenarios through simulation.

Evaluation of On-ramp Control Algorithms

Zhang, Michael
Kim, Taewan
Nie, Xiaojian
Jin, Wenlong
Chu, Lianyu
Recker, Will
2001

The control of a traffic corridor, which consists of two major component - freeway system control and arterial street system control, aims to improve flows on both freeway and arterial streets, and has been demonstrated as an effective means to increase the level of service of a corridor system during peak periods. Ramp metering, or ramp control, has been considered to be a very important component of corridor traffic control. Ramp metering is the application of control devices such as metering signals to limit the number of vehicles entering a freeway. The fundamental philosophy of ramp...

TravInfo Evaluation: Traveler Response Element Willingness to Pay for Traveler Information: Analysis of Wave 2 Broad Area Survey

Wolinetz, Louis
Khattak, Asad J.
Yim, Youngbin
2001

TravInfo is a Field Operational Test (FOT) sponsored by the Federal Highway Administration (FHWA) and California Department of Transportation. It aimed to develop a multi-modal traveler information system for the San Francisco Bay Area, combining public and private sector talents. The Broad Area Study is part of the TravInfo FOT evaluation. This paper addresses issues on the willingness to pay for traveler information. Two waves of telephone surveys of Bay Area households were conducted, one prior to and one after the Field Operational Test. The initial survey was conducted in November...

Commuter Response To Traffic Information On An Incident

Koo, Ronald
Yim, Youngbin
1998

This paper presents and discusses how traffic information is obtained and how it affects travel behavior when a major freeway is congested. Immediately following a major highway incident south of San Francisco which caused congestion, a telephone survey was conducted of commuters who utilize the affected corridor of highway. The behavior of commuters before and during their commute at the time of the incident was determined, including obtaining traffic information and how the information influenced changes in route, mode of travel and departure time. The results of the survey suggest that...

Coding Of Road Information For Automated Highways

Guldner, J.
Patwardhan, S.
Tan, H.
Zhang, W.
1997

This paper discusses coding of road information in a lateral reference system using magnetic markers designed for Automated Highway Systems ( AHS). The coding is utilized to communicate road information such as up- coming road geometry or lane merges/diverges from the roadway infrastructure to AHS vehicles. The work presented here is based on experiences with the preparation of the I-15 test track near San Diego, CA, for the National AHS Consortium demonstration in 1997. Information about road features was encoded into the magnets used as a lateral reference system for automatic steering...

Trav Info Evaluation (Technology Element ) Traveler Information Center (TIC) Study: System Reliability and Communications Interface

Miller, Mark
Loukakos, Dimitri
1998

TravInfo is a Field Operational Test of advanced traveler information systems for the San Francisco Bay Area, sponsored by the Federal Highway Administration (FHWA). The project involves a public/private partnership which seeks to compile, integrate and broadly disseminate timely and accurate multi-modal traveler information through commercial products and services. The public sector component centers on the Traveler Information Center (TIC), which collects and integrates both static and dynamic traveler information. The TIC began operations in September 1996 and will operate as an FOT...