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Showing papers on "Intelligent transportation system published in 1991"


01 Dec 1991
TL;DR: In this paper, an automated intelligent vehicle/highway system (IVHS) is described, and a four-layer hierarchical control architecture is proposed to decompose this problem into more manageable units.
Abstract: Key features of one automated intelligent vehicle/highway system (IVHS) are outlined, it is shown how core driver decisions are improved, a basic IVHS control system architecture is proposed, and a design of some control subsystems is offered. Some experimental work is summarized. A system that promises a threefold increase in capacity is outlined, and a four-layer hierarchical control architecture that decomposes this problem into more manageable units is proposed. >

1,268 citations


Journal ArticleDOI
J.G. Bender1
TL;DR: A comprehensive systems study of the factors influencing the design, development, and deployment of an intelligent vehicle highway system is summarized.
Abstract: A comprehensive systems study of the factors influencing the design, development, and deployment of an intelligent vehicle highway system is summarized. Candidate system concepts and system implementation strategies that have a high potential for successful deployment with a minimum of disruptive influence and cost impact on the current highway system are identified and analyzed. A system concept is recommended together with a plan for its development and deployment. >

210 citations


Proceedings ArticleDOI
01 Oct 1991
TL;DR: In this paper, the authors present a sketch of a general architectural framework within which IVHS systems can carry out a wide range of management and control functions, including stabilizing individual vehicles along nominal trajectories to adapting traffic flows to changing demands.
Abstract: The development of a robust, unified systems architecture is an important problem in IVHS technology. This paper presents a sketch of a general architectural framework within which IVHS systems can carry out a wide range of management and control functions. The most important aspect of the work reported here is the definition of two parallel and compatible architectures suitable in the first case for ATMS and ATIS functions, where the driver controls the vehicle, and in the second case for AVCS functions, where the vehicle is under automatic control. The tasks that must be accomplished within either architecture are differentiated across four dimensions: • function - the functions range from stabilizing individual vehicles along nominal trajectories to adapting traffic flows to changing demands; • time scale - the frequency of decisions and responses varies from under 1 s for continuous control of vehicles to several hours for network flow optimization; • spatial scope - the impact of a control action can vary from a single vehicle to the traffic in the entire network; • information span -- satisfactory accomplishment of the task will require information ranging from that referring to a single vehicle to that which spans system-wide flows. The architecture that we outline incorporates a hierarchy of five layers. This hierarchy helps to formulate a structured, modular approach to the development of IVHS because: • The hierarchy satisfactorily resolves all four dimensions of difference in the tasks. • Each layer presents a standard reference model to the layer above it. This provides a, "clean" interface between layers, and the design of each layer can proceed independently using the reference model of the layer below. When standardized, the reference model serve as IVHS open systems architecture. • Communication takes place only between adjacent layers and between peer layers. This will help specify the communication capabilities needed to support the control system. For the ATMS and ATIS functions, in which the driver is in control of the vehicle the tasks are arranged in the following five layers: the physical, regulation, planning, link and network layers. For the most advanced AVCS functions, in which driving tasks are fully automated, the five layers are: physical, vehicle regulation, coordination, link and network. The corresponding layers in the two architectures are functionally similar, although the reference models are significantly different. The functions and the information requirements of the two architectures are sufficiently similar that we strongly urge that future work aimed at successive refinements of either architecture should insist on a graceful transition to the other architecture. In practice, this is most likely to mean that the ATMS and ATIS systems should be designed to accommodate the extensions to the additional features envisaged in a fully automated AVCS system. The modular, hierarchical nature of the architectural framework we have proposed makes it possible to do so from the start, before the AVCS details are fully worked out, and without significant additional cost. The basic motivation for this work is to invite discussion on IVHS architectures from relevant participants including transportation agencies, automobile manufacturers, control and communications equipment developers, and the research community. We have deliberately sketched an idealized portrait of the fully automated AVCS scenario and avoided the important concerns of system evolution in order to sharpen discussion.

182 citations


01 Mar 1991
TL;DR: The early initiatives of the Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communication technologies that most benefit public transportation, are described in this article.
Abstract: This report documents one of the early initiatives of UMTA's Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communication technologies that most benefit public transportation. This report contains the results of a limited investigation of the extent of adoption of advanced technology in the provision of public transportation service in North America. It focused on some of the most innovative or comprehensive implementations, categorized broadly under the APTS program elements of Market Development, Customer Interface, Vehicle Operations and Communications, and High Occupancy Vehicle Facility Operations. The objective of this effort was to increase the industry's knowledge of successful applications of advanced technologies with the expectation that this will lead to their widespread adoption.

122 citations


Journal ArticleDOI
TL;DR: The status of plans and projects for intelligent vehicle-highway systems (IVHS) in Europe, Japan, and the US is examined in this article, where four broad areas covered by IVHS are described.
Abstract: The status of plans and projects for intelligent vehicle-highway systems (IVHS) in Europe, Japan, and the US is examined. The four broad areas covered by IVHS are described. They are advanced traffic management systems. advanced traveler information systems commercial vehicle operations systems, and advanced vehicle control systems. A variety of projects in Europe, Japan, and the US which aim at proving the feasibility and practicality of IVHS are described. Socioeconomic factors then could delay or even arrest the development of IVHS are examined. >

101 citations


01 May 1991
TL;DR: In this paper, the authors describe advanced driver information systems that should appear in cars of the early 21st century, and propose a systems engineering method for selecting the most beneficial systems (functions) of interest were cellular phone, navigation/route guidance, roadway hazard warning, traffic information, vehicle monitoring, entertainment, in-car signing, motorist services, and incar offices.
Abstract: This report describes advanced driver information systems that should appear in cars of the early 21st century, and proposes a systems engineering method for selecting the most beneficial systems. Systems (functions) of interest were cellular phone, navigation/route guidance, roadway hazard warning, traffic information, vehicle monitoring, entertainment, in-car signing, motorist services, and in-car offices. For each system, the reduction of accidents (59.3%), benefits to traffic operations (39.4%), and driver wants (0.5%) and needs (0.8%) were considered. The accident scores were based on the impact of features on causal factors of accidents (e.g., inattention, excessive speed, etc.). Benefits to traffic operations were estimated from changes in mode choice (e.g., use of public transportation), route choice, and traffic flow (e.g., eliminating peak congestion). Driver wants were based on a focus group study. Driver needs were assessed from the impact of each feature on driver behavior for three representative trip scenarios (work, personal business, and social/recreational). Using these schemes, features of each system were ranked from most to least beneficial. From this and other information, the first five systems listed above were chosen for further study. Features ranked as particularly beneficial provided information about roadway hazards (crash site, construction, railroad crossing), congestion traffic rules, freeway management, path control (e.g., headlight out), and trip planning. Information elements (specific units of information) were identified for these features and prioritized.

69 citations


Journal ArticleDOI
TL;DR: The Los Angeles Automated Traffic Surveillance and Control (ATSAC) System is described, emphasizing those features that provide a powerful and flexible capability to manage traffic.
Abstract: The Los Angeles Automated Traffic Surveillance and Control (ATSAC) System is described, emphasizing those features that provide a powerful and flexible capability to manage traffic. Many traffic detectors are used to collect data used for critical intersection control, traffic responsive control in networks, real-time surveillance of traffic conditions using color-graphic monitors, real-time evaluation of system performance, and automated generation of traffic signal timing plans. Closed-circuit television is used to provide additional information regarding the cause of congestion. Manual control of intersections from the control center is used to correct nonrecurring congestion. The hierarchical system architecture consists of a very fast supervisor computer networked with the control console, color-graphic monitors, and area computers that communicate with up to 400 intersections and 1600 detectors each. An evaluation of system performance concluded that stops were reduced by 35%, intersection delay by 20%, travel time by 13%, fuel consumption by 12.5%, and air emissions by 10%. The benefit/cost was 9.8:1, and the system paid for itself in less than one year. >

44 citations


Book
01 Jan 1991
TL;DR: In this article, the authors present the results of a study to assess the application of advanced technologies in relieving urban traffic congestion and recommend the urgent need for a national program for developing, demonstrating and implementing advanced transportation technologies.
Abstract: This report presents the results of a study to assess the application of advanced technologies in relieving urban traffic congestion. Technologies have been reviewed in the areas of traveler information systems, traffic control systems and automatic vehicle control systems. The study also includes a brief review of the application of these technologies to transit and rideshare needs. Both qualitative and quantitative assessments of a broad range of technologies were undertaken in order to select the three most promising technologies available for short-term implementation. These technologies comprise the radio data system for traffic information broadcasting, externally-linked route guidance, and adaptive traffic control. Detailed benefit-cost analyses were performed on these technologies, together with a review of the funding sources, jurisdictional and institutional issues, and consumer and user reactions to the systems. The study included a review of current moves toward a national intelligent vehicle/highway systems (IVHS) program. An outline of the projects and activities to be included in an IVHS program has been prepared, along with a preliminary time schedule. These activities have been grouped into advanced traveler information systems (ATIS), advanced traffic management systems (ATMS), fleet management and control systems (FMCS), and automatic vehicle control systems (AVCS). The report concludes by recommending the urgent need for a national program for developing, demonstrating and implementing advanced transportation technologies.

41 citations


01 Aug 1991
TL;DR: In this paper, a local indirect adaptive control scheme for non-linear systems is proposed for monotonically decreasing the magnitude of deviations of each system's state from its sink manifold provided that the exogenous input is varying sufficiently slowly and the parameter error is sufficiently small.
Abstract: We consider the class of interconnected non-linear dynamic systems suggested by the problem of longitudinal and lateral control of a platoon of vehicles on automated highways. After describing the physical setting from which the control problem arises, we propose a local indirect adaptive control scheme for this class of interconnected non-linear systems. Then, we establish that the proposed local adaptive control scheme is suitable for monotonically decreasing the magnitude of deviations of each dynamic system's state from its sink manifold provided that (a) the exogenous input is varying sufficiently slowly and (b) the parameter error is sufficiently small. As a consequence, these deviations are bounded with a bound independent of the number of subsystems in the interconnection.

32 citations


01 Jun 1991
TL;DR: Guensler and Geraghty as mentioned in this paper presented the state of uncertainty in different transportation and air quality issues, the importance of clarifying and resolving these issues, and the general areas of research and potential projects that may be proposed during Fiscal Years 1991-1996 to address these uncertainties.
Abstract: Author(s): Guensler, Randall L; Geraghty, Anne B | Abstract: Presented at the Air and Waste Management Association 84th Annual Meeting a Exhibition, Vancouver, British ColumbiaWith the passage of the California Clean Air Act (CCAA) of 1988 and the Federal Clean Air Act (CAA) amendments of 1990, there is significant interest on the part of federal, state, and local agencies in research that will provide accurate methods to evaluate the emission reduction effectiveness of transportation strategies. The results of such research would be used to design projects and packages that would reduce transportation related emissions in the most cost-effective manner.Determining what research projects should be undertaken in a resource constrained environment is a difficult task. Regulators must determine which research projects are likely to result in the most useful information, but they face this task without knowing specifically what current methodologies and assumptions result in the greatest estimation uncertainty. General difficulties in targeting the most effective research areas is coupled with the fact that emission inventory expertise incorporates two distinctly separate areas: knowledge of vehicle activity and vehicle emissions rates.This report describes the state of uncertainty in different transportation and air quality issues, the importance of clarifying and resolving these issues, and the general areas of research and potential projects that may be proposed during Fiscal Years 1991-1996 to address these uncertainties. We consider this paper to be a starting point for discussion, from which a full research agenda is likely to be prepared.This paper describes the emission inventory for motor vehicles and discusses the importance and relevance of the emission modeling methodologies to the ultimate research efforts. Five analytical sections follow: vehicle emission rates, vehicle activity: transportation control measure analysis, the relationship between land use, transportation, and air quality, and advanced highway technologies. A description of the policy concerns facing regulatory agencies is then addressed. Finally, conclusions are presented and short term recommendations are provided for consideration.

31 citations


Journal Article
TL;DR: The PATH program has placed a stronger emphasis on the Advanced Vehicle Control Systems (AVCS) aspect of IVHS than other current programs have, based on the potential that AVCS appear to offer for very significant improvements in capacity and safety.
Abstract: Intelligent Vehicle/Highway Systems (IVHS) are intended to improve the productivity (capacity) and safety of the road transportation system. The PATH program has placed a stronger emphasis on the Advanced Vehicle Control Systems (AVCS) aspect of IVHS than other current programs have, based on the potential that AVCS appear to offer for very significant improvements in capacity and safety. This paper explains how that potential for improvement has been estimated, and illustrates with some sample estimates of the lane capacity that could be achieved by operating vehicles in fully automated platoons. AVCS was subdivided into three evolutionary stages of development. AVCS I systems will provide driver warning and assistance, to help drivers avoid potential accident situations, while the drivers retain control of their vehicles. AVCS II systems will provide for full automation of vehicle steering and engine and breaking functions when the vehicles are operated on special restricted-access links in the highway network, while AVCS III will extend the AVCS II type of automation to complete networks, with automatic routing and scheduling of trips in the automated network.


Proceedings ArticleDOI
01 Oct 1991
TL;DR: This study has addressed the experimental and analytical challenges involved in wide-area sensing, large-volume data processing, and both deterministic and statistical analyses of the data which will characterize this so-called, "Vehicle Motion Environment" (VME).
Abstract: A concept is presented for creating a measurement system that can quantify the specific motions which vehicles exhibit as they move in traffic, under the full array of traffic operations. Such quantification is seen as crucial to the development of automatic collision prevention systems and has spinoff utility for the study of many other issues in human factors and vehicle and highway engineering. This study has addressed the experimental and analytical challenges involved in wide-area sensing, large-volume data processing, and both deterministic and statistical analyses of the data which will characterize this so-called, "Vehicle Motion Environment" (VME). The basic concept which appears to be feasible for such measurements involves a remote sensor which is installed at the roadside, probably on a tall pole, and which produces electro-optic images of the traffic stream and converts them into a permanent data file of the quantified trajectory for each motor vehicle passing through the field of view. The paper covers the performance specifications for the VME measurement system plus considerations for the measurement package and the subsequent processing needed for deriving the variables of interest. Various applications of the VME system are also addressed.

Journal ArticleDOI
A.M. Kirson1
TL;DR: Some of the communications technologies that may be considered for IVHS/ADIS implementation are described, with an emphasis on wide-area RF data communications.
Abstract: Advanced Driver Information Systems (ADIS)P, a subset of Intelligent Vehicle Highway Systems (IVHS), are considered. Some of the communications technologies that may be considered for IVHS/ADIS implementation are described, with an emphasis on wide-area RF data communications. The discussion covers communications between the infrastructure and the vehicle fleet, and not the connections between the roadside equipment and the traffic management center. The steps in designing an RF data system for IVHS/ADIS are reviewed, and design tradeoffs are discussed. >

Journal Article
TL;DR: A conceptual framework for executing real-time diversion of traffic during congestion-causing events, by making efficient use of the available capacities in the highway network, is presented in this paper.
Abstract: The development of a real-time traffic diversion control system for integrated freeway and arterial networks, as part of the most currently envisioned Intelligent Vehicle/Highway System (IVHS) is the topic of this paper. The objective of the traffic control system referred to as 'Smartnet' is to use real-time data to divert traffic from freeway to arterial networks so as to reduce congestion and improve drivers' travel time. The freeway network chosen for this work is the l-395 freeway corridor area in Northern Virginia, between the Capital Beltway and the District of Columbia. The arterials designated as alternative routes for diversion were primarily chosen to comply to network conditions and to conform with expected driver behavior in route selection. In addition, the route capacity, its associated ramps, and the normal flow volume were also considered in this selection process. The diversion strategies under this approach are based on the highway system performance. The aim is to optimize the system's performance as a whole.

Journal ArticleDOI
TL;DR: The role of information in road transport is analysed from the viewpoints of the individual drivers and from the viewpoint of the traffic manager.

Proceedings ArticleDOI
01 Oct 1991
TL;DR: A possible integration framework which essentially acts to decouple RTI applications from communications networks is described, which leads to the notion of a virtual RTI network and is currently under investigation to determine its viability and applicability.
Abstract: The field of Road Transport Informatics (RTI) has spurred a substantial interest in the development and adaptation of a diverse range of technologies for vehicle-infrastructure communications. Candidate technologies for early implementation include FM RDS-TMC, short-range beacons and cellular mobile radio GSM. This paper reviews some of the major characteristics of these systems and debates some of the issues influencing the design and integration of communications technologies for RTI. Next, a possible integration framework which essentially acts to decouple RTI applications from communications networks is described. The aim is to facilitate end-to-end communications between any two application systems which need to communicate, regardless of the network to which each is attached. This concept leads to the notion of a virtual RTI network and is currently under investigation to determine its viability and applicability.



Journal Article
TL;DR: A sketch of a general architectural framework within which IVHS systems can carry out a wide range of management and control functions is presented and an idealized portrait of the fully automated AVCS scenario is sketched in order to sharpen discussion.
Abstract: Presents a sketch of a system architecture for the control and management tasks of an intelligent vehicle/highway system (IVHS)


Proceedings ArticleDOI
01 Aug 1991

01 Jan 1991
TL;DR: In this article, the authors discuss the need for a systematic program of research dealing with the behavioral aspects of the new technology and make recommendations for specific studies as part of the agenda.
Abstract: Following a review of the potential noneconomic consequences of deploying an Intelligent Vehicle-Highway System, the paper discusses the need for a systematic program of research dealing with the behavioral aspects of the new technology. A research agenda covering one component of behavioral research is then outlined and recommendations are made for specific studies as part of the agenda.


Journal Article
TL;DR: In this article, the authors presented estimates of accident savings attributed to the intelligent vehicle-highway system (IVHS) and IVHS devices using expert judgment applied to various configurations of accidents, for which data are available in standard sources.
Abstract: Estimates of accident savings ascribed to the intelligent vehicle-highway system (IVHS) and IVHS devices have been published by Mobility 2000. These estimates were obtained through the use of expert judgment applied to various configurations of accidents, for which data are available in standard sources. Similar work has been done in Europe. The availability of in-depth data sets and other more detailed sources enabled estimates to be made on a quantitative basis. Methods used in European and U.S. work are discussed, and results are compared. An account is given of a possible development of the evaluation technique that can provide greater precision and might facilitate the choice between different realizations of the same requirement. Finally, the possibility of interactions among different devices on the same or different vehicles that might hinder safety is identified. The need for systematic configuration management of IVHS is emphasized.



Journal Article
TL;DR: In this article, the authors present the results from a recent survey that summarizes the opinions of experts in a range of fields related to intelligent vehicle-highway systems (IVHS) including motorist information, vehicle navigation, vehicle location and identification, route guidance, automatic tolls and road pricing, collision avoidance and warning, speed and headway keeping, automated highways, and automated guideway systems.
Abstract: The development of intelligent vehicle-highway systems (IVHS) in the United States is characterized by a high level of uncertainty regarding system development and social response. Although there appears to be much interest and support for pursuing this new approach for increasing the capacity, efficiency, and safety of road transportation, it is difficult to say at this point what set of functions, technologies, standards, and institutional arrangements will eventually evolve into an accepted architecture for IVHS in the United States. There is uncertainty about the financing of system development, the outcome of competing systems and desired functions, consumer acceptance of the concepts and products, and about almost every aspect of the development of IVHS. This paper presents the results from a recent survey that summarizes the opinions of experts in a range of fields related to IVHS. The Delphi forecasting methodology was used to generate a consensus on predicted market penetration for various IVHS including motorist information, vehicle navigation, vehicle location and identification, route guidance, automatic tolls and road pricing, collision avoidance and warning, speed and headway keeping, automated highways, and automated guideway systems. In this paper the system is explained, the market forecasts are presented, related institutional and technical barriers are identified, and the results of the survey are compared with similar surveys conducted in Europe and the United States.

01 Jan 1991
TL;DR: In this article, the authors focused on short-term commuter respnse to unexpected (incident-induced) congestion and investigated factors which influence diversion from the regular route and possible return (after diversion to the normal route).
Abstract: Incident-induced congestion is a major source of delay and frustration for drivers in large urban areas. Intelligent Vehicle Highway Systems (IVHS) may address at least part of the incident-induced congestion problem. To fully utilize the potential of IVHS, transportation managers need to understand enroute driver response to congestion. This study focused on short-term commuter respnse to unexpected (incident-induced) congestion. It investigated factors which influence diversion from the regular route and possible return (after diversion to the regular route. (A)

Journal Article
M Coyle1
TL;DR: A driving simulator is presented to design and evaluate the safety and effectiveness of a headsup display and shows the importance of the synthesis and management of this information.
Abstract: The authors examine headsup displays as a means of information display. The synthesis and management of this information is crucial so as to not overload the driver and create safety hazards. The authors present a driving simulator created to design and evaluate the safety and effectiveness of a headsup display.