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.

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...

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...

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...

Effectiveness of California’s High Occupancy Vehicle (HOV) System

Varaiya, Pravin
2007

This is the most extensive empirical evaluation of the effectiveness of California’s HOV system based on data collected from traffic sensors. The evaluation leads to four major conclusions. (1) Since it operates as a single lane freeway, an HOV lane suffers a 20 % capacity loss compared with multi-lane freeways. (2) HOV lanes are either under-utilized or suffer degraded operations. (3) HOV lanes do not measurably increase car-pooling. (4) HOV lanes do not reduce overall congestion in a reasonably well-managed system.

The Automated Highway System / Street Interface: Final Report

Hall, Randolph
Chin, Chinan
Gadgil, Nishad
2003

The economics of roadways, and their variability in demand, favor construction of multi-layered and inter-connected networks. Different network layers are designed to different standards and to perform somewhat different functions, though all provide the common function of mobility for a reasonably homogeneous class of vehicles. Yet interfaces have been constructed to provide a smooth transition between network layers, with little delay and inconvenience to travelers. This project has investigated interfaces between an automated highway network layer and city streets. The report...

TASK A-1: Motivations Behind Electronic Road Pricing. What is the Driving Force Behind the Worldwide Rise in Tolling? A Review of Innovative Road Pricing from Across the Globe

Kalauskas, Rebecca
Taylor, Brian D.
Iseki, Hiroyuki
2009

The report identifies the motivations behind and objectives of specific road pricing initiatives, and to explore why such policies are becoming an increasingly popular approach to transportation finance and management. Over the past 15 years, electronic road pricing projects have appeared in a variety of forms across the globe – from the Interstate 15 High-occupancy toll (HOT) Lanes in San Diego County, to the congestion cordon pricing scheme in central London, to the German weight-distance truck toll system, to the Oregon mileage-based user fees pilot program. While the stated objectives...