Infrastructure

Continuum Approximation Approach to Bus Network Design under Spatially Heterogeneous Demand

Ouyang, Yanfeng
Nourbakhsh, Seyed Mohammad
Cassidy, Michael J.
2014

A methodological framework is formulated so that continuum approximation techniques can be used to design bus networks for cities where travel demand varies gradually over space. The bus-route configurations that result consist of (i) a main, possibly city-wide grid with relatively large physical spacings between its parallel routes and the stops along those routes; together with (ii) one or more local grids with more closely-spaced routes and stops that serve neighborhoods of higher demand densities. The so-called power-of-two concept is borrowed from the field of inventory control, and...

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...

Development and Implementation of a Vehicle-Centered Fault Diagnostic and Management System for the Extended PATH-AHS Architecture: Part I

Yi, Jingang
Suryanarayanan, Shashikanth
Howell, Adam
Horowitz, Roberto
Tomizuka, Masayoshi
Hedrick, Karl
Alvarez, Luis
2002

The purpose of this project is to extend and integrate existing results on fault diagnostics and fault management for passenger vehicles used in automated highway systems (AHS). These results have been combined to form a fault diagnostic and management system for the longitudinal and lateral control systems of the automated vehicles which has a hierarchical framework that complements the established PATH control system. Furthermore, the fault diagnostic module effectively monitors the sensors and actuators required for longitudinal and lateral control, while the fault handling module...

Address Resolution in One Lane Automated Highway Systems

Bana, Soheila V.
Varaiya, Pravin
1999

Address Resolution Protocols (ARP) are used in Automated Highway Systems (AHS) to establish communication among vehicles. The purpose of the ARP is to determine the network address of neighboring vehicles. We are proposing an innovative solution that takes advantage of the automated road infrastructure. For providing addresses initially and uses the communication network itself for updating the network communication addresses in a one lane automated highway system. The protocol has been modeled using PROMELA [1], and simulated and verified by SPIN [2]. SPIN is a tool for analyzing the...

U.S. Shared-use Vehicle Survey Findings: Opportunities and Obstacles for Carsharing and Station Car Growth

Shaheen, Susan A.
Meyn, Mollyanne
Wipyewski, Kamill
2003

Shared-use vehicle services provide members access to a vehicle fleet for use on an as needed basis, without the hassles and costs of individual auto ownership. From June 2001 to July 2002, the authors surveyed 18 U.S. shared-use vehicle organizations on a range of topics, including organizational size, partnerships, pricing, costs, and technology. While survey findings demonstrate a decline in the number of organizational starts in the last year, operational launches into new cities, membership, and fleet size continue to increase. Several growth-oriented organizations are responsible for...

Expanding the Urban Transportation Infrastructure Through Concession Agreements: Lessons from Latin America

Rodriguez, DA
1999

Driven by fiscal constraints and disappointment with the performance of state-provided services, national and subnational governments have turned to the private sector for solutions in financing, constructing, and providing transportation services. Key concession package features and their effect on reaching closure in urban transportation agreements are analyzed. Case studies drawn from the major attempts to develop urban transportation infrastructures in Latin America through concession agreements are considered. Results indicate that features common to large infrastructure...

SmartAHS and SHIFT Enhancements, Persistence and Query Interpretation

Misener, Jim
2000

We have enhanced and "tuned" SmartAHS and SHIFT to address a wide variety of functional and user needs. SmartAHS has become an important microsimulation tool for design, analysis and evaluation of AHS - and "pre-AHS" or AHS deployment - concepts and scenarios in dimensions of system performance (i.e., throughput and travel time), safety and comfort. The SmartAHS/Hybrid Systems Tools Interface Format (SHIFT) is the basis for SmartAHS, and it is the general hybrid systems simulator for user-defined AHS architectures.

Message Volumes For Two Examples Of Automated Freeway

Hitchcock, Anthony
1993

In this paper, calculations are made of the volume of messages transmitted between vehicles or between vehicles and the infrastructure, in order to estimate the demand of advanced vehicle control systems (AVCS) for frequency allocations. Two previous conceptual designs for an automated freeway are used to provide a basis for calculations.

GPS/ INS Based Lateral And Longitudinal Control Demonstration: Final Report

Farrell, Jay
Barth, Matthew
Galijan, Randy
Sinko, Jim
1998

This report describes the results of a one year effort to implement and analyze the performance of a Differ- ential Global Positioning System (DGPS) aided Inertial Navigation System (INS) for possible future use in Advanced Vehicle Control Systems (AVCS). The initial premise of this project was that DGPS/INS technology has the potential to serve as a centimeter-level position reference system as necessary for automated driving functions. Key advantages of this approach include: 1) no changes to the highway infrastructure are required; therefore, the DGPS/INS system should be less expensive...