Roads/Highways

PATH ITS Research Digests

Chira-Chavala, Ted
2001

Ramp meters are commonly used to relieve congestion on freeways. What is the value of these systems? Ramp metering can alleviate recurrent, regular traffic congestion, such as that caused by the daily commute. The goal is usually to maintain uninterrupted freeway flow at a certain acceptable level, but it transfers delay to the entrance ramp, where excess demand is forced to wait. This report summarizes ramp metering technologies, reviews the algorithms commonly used with them, and uses a traffic simulation model to identify the benefits and costs of using these systems. We used a...

Driving Intelligence Replacement in a Decision-Oriented Deployment Framework for Driving Automation

Tsao, H.-S. Jacob
Ran, Bin
1996

What some human drivers have done wrong has been blamed for much of the problem associated with the current highway systems. For example, driver inattention, fatigue and other human errors have often been cited as major sources of safety hazard on current highways and human capabilities as major limitations on current highway capacity. Such human deficiencies and the pervasive urban traffic congestion have motivated the concept of Automated Highway Systems (AHS). The fundamental objective of AHS is to achieve user and societal benefits through replacing human driving by automated machine...

Steady State Conditions on Automated Highways

del Castillo, Jose M.
Lovell, David J.
Daganzo, Carlos F.
1995

This paper is concerned with technical investigations of traffic operations on automated highways. Estimates are made of the steady-state capacity of such freeways, paying particular attention to the effect of entry and exit maneuvers. The possibility of scheduling departing vehicles appropriately into platoons to minimize extraneous maneuvers is investigated. Characteristics of urban areas likely to be candidates for automated freeways are discussed, and some shortcomings of automated freeways, vis-à-vis conventional freeways, are pointed out. Finally, some areas of future research needs...

Experimental Studies on High Speed Vehicle Steering Control with Magnetic Marker Referencing System

Tan, Han-Shue
Bougler, Bndicte
2000

This project is a one-and-half year research and experimental effort that builds on the results of as well as supplements the efforts in MOU 250, "Experimental Studies on Vehicle Control Systems." It focuses on an emerging issue of the high-speed steering control: how to conduct robust automatic vehicle steering control at highway speed based on a look-down lateral sensing system.

Automated Highway Systems Operating Strategies and Events: A Driver’s Perspective

Tsao, H.-S. Jacob
Hall, Randolph
Shladover, Steven
1997

Automated Highway Systems (AHS) have the potential for offering large capacity and safety gains without requiring significant amounts of additional right-of-way. Since the general public will be the users of the AHS, human factors must play a pivotal role in the research and development of AVCS technologies and AHS operation. This paper focuses on fully automated AHS.To ensure the identification of all major human factors issues, we have identified major options for operating fully automated AHS. These options are categorized in the following four dimensions: separation of traffic,...

California System Architecture For Intelligent Transportation: Models For Transportation Systems Management

Hall, Randolph
Thakker, Viral
1998

In 1996, the Federal Highway Administration completed a program to develop a national system architecture (NSA) for intelligent-transportation-systems. This report presents recommendations on methodologies by which system architecture can be used to improve the deployment of transportation management projects, with emphasis on multi-jurisdictional projects. The report is part of a larger project addressing the deployment of an ITS system architecture in California. The project as a whole is led by Claremont Graduate School, and is documented in a separate report.

Configuration And Maneuvers In Safety-consciously Designed Ahs Configuration

Hitchcock, Anthony
1995

This paper sets out a configuration for an Automated Highway System (AHS) which is believed to have advantages from a safety viewpoint. The configuration and operating principles are described. The scheme requires that vehicles change lanes directly from platoon to platoon, and that entry and exit be made also without platoons merging or splitting on the automated lanes. The protocols for the maneuvers needed are described in detail.

Travinfo Evalution (technology Element) Traveler Information Center (tic) Study (september 1996 - June 1997)

Miller, Mark A.
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...

Travinfo Field Operational Test Evaluation Plan

Hall, Randolph
Yim, Y. B.
Khattak, Asad
Miller, Mark
Weissenberger, Stein
1995

TravInfo is a Field Operational Test (FOT) sponsored by the U.S. Federal Highway Administration. The goal of the project is to implement a centralized traveler information center to collect, integrate, and broadly disseminate timely and accurate traveler information in the San Francisco Bay Area. This evaluation plan describes the scope, methods, and procedures to measure the effectiveness of the project. The TravInfo evaluation will contain four evaluation elements: institutional, technology, traveler response, and network performance.

Some Aspects of the Market for Broadcast Traffic Information

Malchow, Matthew
Kanafani, Adib
1999

In recent years, planners have looked toward traffic information systems as an immediate solution to the congestion on U.S. highways. ITS systems are low-cost relative to many alternatives, and simple implementation allows for quick results. Alongside these investments has been research investigating the use of information systems by drivers and the results to be expected. Many studies have shown that the primary source of information for drivers has been broadcast systems such as the radio (e.g. Yim et al., 1997). Additional research has addressed other media which are used to transmit...