Roads/Highways

A Congestion Mechanism for Uphill Expressways, Part I: The Shoulder Lane "Release Valve"

Patire, Anthony D.
Cassidy, Michael J.
2010

A mechanism is unveiled by which congestion forms and persists near the base of an uphill expressway segment, causing significant reductions in output flow. The traffic condition in the expressway's shoulder lane is key to the mechanism. When shoulder-lane flow was low, drivers maneuvered around speed disturbances that periodically arose in the median lane. The shoulder lane accommodated high rates of vehicle migrations, thus acting as a "release valve" for the excess accumulation created by the speed disturbances. The release valve failed only when demand increased later in the rush. The...

Weaving Analysis, Evaluation and Refinement

Skabardonis, Alexander
Kim, Amy
2010

Weaving sections are common design elements on freeway facilities such as near ramps and freeway to-freeway connectors. When the traffic demands exceed the capacity at weaving areas congestion may occur, which affects the operation of the entire freeway section. Traffic operational problems also may exist at weaving areas even when traffic demands are less than capacity because of the complexity of vehicle interactions, resulting in poor level of service (LOS) and potential safety problems. Existing procedures for the design and analysis of freeway weaving sections have several...

Traffic Modeling To Evaluate Potential Benefits Of Advanced Traffic Management And In-vehicle Information Systems In A Freeway/Arterial Corridor

Gardes, Yonnel
1990

This study includes a literature review of existing traffic simulation models potentially suited for evaluating advanced traffic control strategies and in-vehicle information systems within an integrated freeway/ arterial corridor. Chapter 1 presents a literature review and identification of candidate models. Chapter 2 contains a preliminary screening of candidate models. Chapter 3 presents an in-depth evaluation of short list of models. And, Chapter 4 gives conclusions of the research and recommendations for future directions.

An Integrated Physical/link-access Layer Model Of Packet Radio Architectures

Polydoros, Andreas
1994

The goal of this effort is to devise and analyze an integrated Physical/ Link-Access Layer Model of packet Radio Architectures, with application to the PATH/IVHS (Intelligent Vehicle Highway Systems) communication sub- system design between vehicles and infrastructure, as well as between vehicles on the move. The present report contributes to a generic conceptual model for system evaluation which can be used for quantification of the interaction between network layers. The research tasks that have been performed for achieving the project objectives include collection of data requirements...

An Analysis of HOT Lanes in North Carolina

Benjamin, JM
Sakano, R
McKinney, B
Khattak, AJ
Rodriguez, DA
Gaskin, C
2007

Many medium and small-size metropolitan areas in the U.S. face increasing traffic problems similar to large metropolitan areas. These metropolitan areas have responded primarily by expanding their road network and capacity. This paper explores the possibility of using a HOT lane in a medium-size metropolitan area for the same purpose. A detailed analysis and a suggested HOT lane solution are prepared for Greensboro-Winston-Salem-High Point metropolitan area. While high congestion are not widespread in the region now, a highway corridor is identified based on forecasted high...

A Fuzzy Rule-Based Controller For Automotive Vehicle Guidance

Hessburg, Thomas
Tomizuka, Masayoshi
1991

A fuzzy rule-based controller is applied to lateral guidance of a vehicle for an automated highway system. The fuzzy rules, based on human drivers' experiences, are developed to track the center of a lane in the presence of external disturbances and over a range of vehicle operating conditions.

Intelligent Vehicle/highway System Safety: Multiple Collisions In Automated Highway Systems

Hitchcock, Anthony
1995

In this report, a comparison is drawn between the casualty rates per failure on an automated highway system (AHS) according to the longitudinal control configuration used. The comparison is drawn between closed-spaced platooning, vehicle following of the types used in Autonomous Intelligent Cruise Control (AICC) and Cooperative Intelligent Cruise Control, and a point-following configuration (PFC). The model used permits evaluation of the consequences of a failure, allowing for the multiple collisions that usually ensue.

Deployment and Evaluation of Real-Time Vehicle Reidentification from an Operations Perspective

Coifman, Benjamin
Varaiya, Pravin
2002

This Section improves upon the vehicle reidentification algorithm presented in Coifman and Cassidy (in press) for consecutive detector stations on a freeway; in the algorithm, a vehicle measurement made at a downstream detector station is matched with the vehicle's corresponding measurement at an upstream station. The work should be applicable to any detector technology capable of extracting a reproducible vehicle measurement, or vehicle signature. The algorithm is presented using measured vehicle lengths from conventional dual loop detectors; however it could easily be adapted to match...

Longitudinal Control Development For IVHS Fully Automated And Semi - Automated System: Phase III

Hedrick, J. K.
Garg, V.
Gerdes, J. C.
Maciuca, D. B.
Swaroop, D.
1997

This report focuses on longitudinal issues regarding modeling and control of vehicles in an Intelligent Transportation Systems (ITS) setting. Specifically, the report addresses the issue of vehicle control in an automated highway system, brake actuation and brake control. Recent research findings in the area of automated vehicle platooning on isolated lanes of an automated highway are included. Performance specifications, control system architecture, vehicle control algorithms, actuator and sensor specifications and communication requirements are also discussed. The report also addresses...

Highway Electrification And Automation Technologies - Regional Impacts Analysis Project: Phase I: Baseline Scenario Data Analysis

Scag
Path
1993

The Highway Electrification and Automation Technologies Regional Impacts Analysis Project addresses the transportation-related problems of freeway congestion, air pollution, and dependence on fossil fuels in southern California. This report presents a documentation of the basis for the impacts analysis. It contains sections on data collected, baseline forecast for 2025, and electrification and automation specification scenarios. This report constitutes the final report for Phase I of the project.