Roads/Highways

The Prospects for High Occupancy/Toll (HOT) Lanes: Where Should They Be Implemented

Dahlgren, Joy
2001

There is increasing interest in building new high occupancy toll (HOT) lanes and in converting high occupancy vehicle (HOV) lanes with unused capacity to HOT lanes. Like HOV lanes, HOT lanes provide an incentive for travelers to use HOVs, but unlike HOV lanes, they can always be well utilized by varying the toll over the congested period, thus providing more congestion relief than an HOV lane with unused capacity. This report provides guidelines regarding the circumstances in which HOT, HOV, and mixed flow lanes are most appropriate. Using a queueing model combined with a mode choice model...

Safetrip-21: Connected Traveler

Sengupta, Raja
Misener, Jim
Ahern, Katherine
Chan, Ching-Yao
Gupta, Somak Datta
Jariyasunant, Jerry
Li, Jing-Quan
Long, Christopher
Mai, Eric
Manasseh, Christian
Nowakowski, Christopher
O’Connell, Jessica
Rezai, Shahram
Steelhorst, Michael
Zhang, Liping
Zhang, Wei-Bin
Zhou, Kun
Zhou, Xeusong
2010

The US DOT RITA Volpe Center entered into a cooperative agreement with the California Department of Transportation (Caltrans) to establish the inaugural SafeTrip 21 field test site in the San Francisco Bay area [named Connected Traveler]. Specifically, the site encompasses I-880 from Oakland to San Jose on the east bay and from San Jose to just south of the San Francisco International Airport, along U.S. 101 and California State Route (SR) 82. The site includes the SR-84 Dumbarton Bridge toll crossing, which links I-880 and U.S. 101. Caltrans's partners include the Metropolitan...

Causes of Freeway Productivity Decline and the Opportunities for Gain: A Quantitative Study

Varaiya, Pravin
2008

Work done under TO 5306 led to three accomplistments. First, a measure of freeway productivity was proposed. Second, the causes of productivity decline led to the notion of "congestion pie." Both productivity loss and congestion pie are available at PeMS applications. Third, the study entitled "An Empirical Assessment of Traffic Operations" [1] provides a detailed empirical account of congestion.

Ad-hoc Medium Access Control Protocol Design and Analysis for Vehicle Safety Communications

Sengupta, Raja
Xu, Qing
Mak, Tony
Ko, Jeff
2004

This paper studies the design of ad-hoc Medium Access Control (MAC) protocols for a vehicle or the roadside to send safety messages to other vehicles. Such a protocol is needed by Advanced Vehicle Safety Systems (AVSS) and the national Dedicated Short Range Communications (DSRC) architecture. The problem is formulated to meet the communication requirements of vehicle safety applications and the DSRC multi-channel operation model. We propose several ah-hoc protocols, all based on the principles of repetition coding. Analytical bounds of the protocols' performance are derived. Simulations...

Development of the Advanced Rotary Plow (ARP) for Snow Removal Operations

Tan, Han-Shue
Bu, Fanping
Bougler, Bénédicte
Koo, Shiang-Lung
Nelson, David
Chang, Joanne
Lian, Thang
2006

This final report describes the development and the initial field test of an automated snowblower, focusing on one of the more difficult snow removal operations: blowing snow off the freeway along side a guardrail without touching the guardrail. The objective is to minimize damage to the snowblower, guardrail, and other elements of the infrastructure by deploying highly accurate and robust automated steering. The automatic steering is accomplished by following magnets embedded under the roadway. The development process includes transforming this real-world automated highway winter...

Modeling And Simulation Of The Automated Highway System

Eskafi, Farokh H.
1996

This report presents the hierarchical structure for the control design of an Automated Highway System (AHS). This control hierarchy has four layers: network, link, coordination, and regulation. It is used to model different AHS proposals. Control layers and the internal structure of each layer and the interfaces between then are described. Three basic maneuvers are described: join, split, and change lane. The SmartPath simulation tools are described to enable simulating AHS scenarios. The advantages of SmartPath include providing a graphical interface, providing microsimulation, and also...

Roadway and Work Crew Conspicuity

Barton, Joseph E.
Misener, James A.
2000

Abstract. The work reported here quantitatively addresses the measurement of conspicuity of highway features and Caltrans work zones -- from the perspective of driver detection. The method focused on acquiring and operating on a computational visual signature analysis tool, but it evolved into evaluating the detection process, then selecting and exercising human perception-acquisition models suitable for development into a tool for conspicuity measurement. A composite, quantitative model of conspicuity was developed, verified, and applied to some sample roadside scenes. Key Words....

Lane Assist Systems for Bus Rapid Transit, Volume II: Needs and Requirements

Zhang, Wei-Bin
Shladover, Steven
Cooper, Douglas
Chang, Joanne
Miller, Mark
Chan, Ching-Yao
Bu, Fanping
2007

This report defines the transit service needs that can be met by use of lane assistance systems and the requirements that these systems must meet in order to be useful and safe. The work is based on review of the existing literature and research on the subject of lane assistance, combined with case studies of several transit properties that could potentially benefit from use of lane assist systems. The project team has conducted workshops involving participation by a broad mix of people representing the transit properties in order to learn about the needs that they perceive, as well as...

Fault Tree Analysis Of An Automated Freeway With Vehicle-borne Intelligence

Hitchcock, Anthony
2004

This report summarizes research work conducted under TO4143 at the California PATH ATMS Center at the University of California, Irvine. This project has two tasks: Functionality enhancements of the PARAMICS simulation model through API programming for the on-line simulation application; On-line data fusion algorithm for a better section travel time estimation based on point detector data and probe vehicle data. In order to conduct these two tasks, we complete the following two related studies, which are the basis of the two tasks of this project: Development of the capability-enhanced...

Development and Evaluation of Selected Mobility Applications for VII: Concept of Operations

Shladover, Steven E.
Lu, Xiao-Yun
Cody, Delphine
2009

This report describes the concept of operations for the three mobility applications that PATH is developing and evaluating under the sponsorship of the FHWA Exploratory Advanced Research Program. These applications are intended to use DSRC wireless communications among vehicles and between vehicles and the roadway infrastructure to improve mobility on limited-access highways. The first application combines ramp metering with variable speed limits to enhance control of traffic so that traffic flow breakdowns can be deferred or avoided at bottleneck locations. The second application uses...