Showing papers on "Intelligent transportation system published in 1997"
TL;DR: This research effort focused on developing traffic volume forecasting models for two sites on Northern Virginia's Capital Beltway, and found that the nonparametric regression model was easy to implement, and proved to be portable, performing well at two distinct sties.
Abstract: The capability to forecast traffic volume in an operational setting has been identified as a critical need for intelligent transportation systems (ITS). In particular, traffic volume forecasts will support proactive, dynamic traffic control. However, previous attempts to develop traffic volume forecasting models have met with limited success. This research effort focused on developing traffic volume forecasting models for two sites on Northern Virginia's Capital Beltway. Four models were developed and tested for the freeway traffic flow forecasting problem, which is defined as estimating traffic flow 15 minutes into the future. They were the historical average, time-series, neural network, and nonparametric regression models. The nonparametric regression model significantly outperformed the other models. A Wilcoxon signed-rank test revealed that the nonparametric regression model was easy to implement, and proved to be portable, performing well at two distinct sties. Based on its success, research is ongoing to refine the nonparametric regression model and to extend it to produce multiple interval forecasts.
566 citations
Book•
01 Dec 1997
TL;DR: In this article, the authors present the first integrated study of the role of positioning systems in ITS, the major types of positioning system, the relationship between them, and methods for evaluating their performance.
Abstract: From the Publisher:
Positioning systems, which determine the location of cars, trucks, buses, trains, and airplanes, are critical in the use of intelligent transport systems (ITS) to improve the efficiency and safety of transport systems while making them less congested and less polluting. This book is the first integrated study of the role of positioning systems in ITS, the major types of positioning systems, the relationship between them, and methods for evaluating their performance.
The content is also unique in that it covers the construction and use of maps for positioning, addresses the Global Positioning System (GPS), and discusses emerging positioning technologies such as Quiktrak and cellular mobile telephones. In addition, the book examines both the role of positioning in the architecture of ITS and the suitability of various positioning systems for specific applications. Case studies further illustrate a method for analyzing ITS positioning requirements.
This authoritative reference can help you save time and money by selecting and developing the most appropriate solutions. Specifically, it will help you:
? Determine specifications of positioning systems for ITS
? Identify the different types of positioning systems
? Understand the high-level operation of positioning systems
? Match positioning systems to ITS applications
? Understand high-level mapping issues
? Conceptualize the operation of positioning system components
The book provides a wealth of information highly useful for transportation, electrical, and software engineers who are responsible for integrating positioning systems into broader ITS applications ordesigning new positioning systems for ITS. It is also an important source for positioning systems experts who need to gain a better understanding of ITS.
156 citations
01 Oct 1997
TL;DR: The proposed data model may be sufficiently robust to support intelligent transportation systems (ITS) map database interoperability by maintaining independence among the geographic datum, the events that occur on the transportation system, the geometry to represent the system cartographically, and the paths through the system.
Abstract: Sharing of digital road map databases within and among organizations is dependent on translating user requirements to a data model that supports linear and non-linear location referencing systems. This paper examines issues of creating such a data model with the intent of sharing digital road map databases, and suggests implementation choices that can accommodate a range of applications. The proposal is best characterized as a geographic information system for transportation (GIS-T) enterprise data model suitable for organizations responsible for any and all modes of transportation; e.g. aviation, highways, public transit and railways. The proposed data model may be sufficiently robust to support intelligent transportation systems (ITS) map database interoperability by maintaining independence among the geographic datum, the events that occur on the transportation system, the geometry to represent the system cartographically, and the paths through the system. Sample physical database designs are provided to show how the model might be implemented.
90 citations
01 Jan 1997
TL;DR: One additional parameter vehicle class category is identified, and how some of the traffic related parameters can be measured is discussed, and some innovative ways that have been devised by PATH researchers to accurately measure travel time are given.
Abstract: This article is a continuation of a previous article (see PATH Database reference no. 11197) in which the author examined the the need for traffic surveillance and the parameters that need to be detected. In this article, he identifies one additional parameter vehicle class category, and discusses how some of the traffic related parameters can be measured. He gives an overview of some innovative ways that have been devised by PATH researchers to accurately measure travel time.
63 citations
TL;DR: Two shared-memory and one message-passing algorithms for time-dependent shortest-path algorithms that can be used in real-time ITS applications are designed, implemented, coded and computationally tested on actual and random networks.
Abstract: The development of Intelligent Transportation Systems (ITS) and the resulting need for real-time traffic management and route guidance models require fast shortest-path algorithms that can account for the dynamics of traffic networks. The objective of this paper is to introduce parallel designs for time-dependent shortest-path algorithms that can be used in real-time ITS applications. In this paper, two shared-memory and one message-passing algorithms are designed, implemented, coded and computationally tested on actual and random networks. The reported tests are performed on CRAY supercomputers, but the algorithms can be readily ported to lower-end multiprocessor machines.
53 citations
01 Jan 1997
TL;DR: A review of selected developments over the past decade in the area of modelling commuter decisions, particularly departure time and route choice, day-to-day dynamics of these decisions to interaction with system performance, and the role of information is presented in this paper.
Abstract: This chapter presents a review of selected developments over the past decade in the area of modelling commuter decisions, particularly departure time and route choice, day-to-day dynamics of these decisions to interaction with system performance, and the role of information. The chapter addresses models of departure time and route choice, daily switching decisions, and learning rules. Results of laboratory-like experiments, computer simulations and actual surveys are highlighted. Recent issues arising in connection with IVHS (advanced traveller-information systems) are also discussed. Throughout, issues and challenges facing the travel-behaviour research community are highlighted. (A) For the covering abstract see IRRD 888414.
53 citations
TL;DR: The model presented explicitly considers the stochastic attributes of incident duration, which can be used for predicting the delay that a vehicle would experience as it travels through nonrecurring congestion brought about by an incident.
Abstract: The ability to predict the link travel times is a necessary requirement for most intelligent transportation systems (ITS) applications such as route guidance systems In an urban traffic environment, these travel times are dynamic and stochastic and should be modeled as such, especially during incident conditions In contrast to traditional deterministic incident delay models, the model presented explicitly considers the stochastic attributes of incident duration This new model can be used for predicting the delay that a vehicle would experience as it travels through nonrecurring congestion brought about by an incident The model is operational in the sense that it does not require significant data and computational abilities beyond that which is traditionally used and can be used within traffic models or within actual ITS implementations A mixed discrete and continuous vehicle-delay model is first derived and estimators of the mean and variance of vehicle delay are identified A sensitivity analysis subsequently is performed, and a method for updating the estimated delay as new information becomes available is provided
47 citations
Journal Article•
TL;DR: This article gives an overview of the importance in developing standards and their benefits, in particular, as applied to Intelligent Transportation Systems (ITS).
Abstract: This article gives an overview of the importance in developing standards and their benefits, in particular, as applied to Intelligent Transportation Systems (ITS).
46 citations
TL;DR: There is a need to expand the scope of traditional human factors to include macro-level effects as well as to place greater emphasis on understanding human interactions with other elements of the system.
Abstract: Traffic systems are undergoing enormous change with the advent of Intelligent Transport Systems (ITS). Although productivity and quality of mobility are emerging interests, safety remains the predominant preoccupation of ITS human factors. It should be evident that while intelligent technologies may have the potential to improve traffic safety, they also have the potential to adversely affect it. Ultimately, the effect on safety depends on the specific technologies that are invoked and the manner in which they are incorporated within the vehicle as well as within the larger road transportation system. Current automotive developments can be characterized as technology-centred solutions rather than user-centred solutions. Greater effort must be directed at understanding and accommodating the human element in the road transportation system in order that future transportation objectives can be achieved. There is a need to expand the scope of traditional human factors to include macro-level effects as well as to place greater emphasis on understanding human interactions with other elements of the system. There is also increasing recognition of the urgent need for systematic procedures and criteria for testing the safety of ITS prior to large-scale market penetration. Language: en
43 citations
01 Aug 1997
TL;DR: The 1997 edition of the Freeway Management Handbook as discussed by the authors is an update of the 1983 edition and reflects the tremendous developments in computing and communications technology and the importance of integrated transportation management systems and the development of the concept of Intelligent Transportation Systems.
Abstract: This handbook is an update of the 1983 edition and reflects the tremendous developments in computing and communications technology. It also reflects the importance of "Integrated" Transportation Management Systems and the development of the concept of Intelligent Transportation Systems (ITS). The handbook development began with a survey of current practice, including site visits and interviews, of ten Freeway Management Systems throughout the country. It was developed under the advice of a panel of freeway management practitioners. The 1997 edition is organized in modular fashion with each module addressing a particular aspect or technology of the freeway management task. The modules are stand-alone treatments of particular areas of freeway management but are cross-referenced to reflect their interdependence. Each module is organized as follows: INTRODUCTION - Including Module Objective and Scope; DECISION PROCESS - Partners and Consensus Building, Establishing Goals and Objectives, Performance Criteria, Functional Requirements, System Architectures, Identification and Screening of Technologies, and Implementation; TECHNIQUES AND TECHNOLOGIES - Applications specific to the module; LESSONS LEARNED - Experiences and observations from operating systems; and REFERENCES - Comprehensive list of references used in module preparation. Specific modules are as follows: Introduction and Executive Summary; (1) Freeway Management Concepts; (2) Decision Process; (3) Surveillance; (4) Lane Control; (5) Ramp Control; (6) HOV Concepts; (7) Information Dissemination; (8) Incident Management; (9) Communications; (10) Control Centers; and (11) Economic Analysis.
41 citations
09 Nov 1997
TL;DR: Through simulations, the ALLONS-D scheme is shown to be suitable for adaptive control of an isolated intersection and an extension of the scheme to provide network-wide optimization of traffic signals is explained in the form of a two-layer scheme.
Abstract: ALLONS-D is a decentralized real-time traffic control scheme. Through simulations, the scheme is shown to be suitable for adaptive control of an isolated intersection. An efficient tree searching algorithm, constrained only by a maximum and minimum green time per phase, is used to find a traffic signal plan that minimizes delay. Differences between ALLONS-D and other real-time traffic control schemes, such as OPAC, are described. The scheme can also be used to reduce travel times on transit routes. For arterial networks of intersections, ALLONS-D is capable of inducing a level of coordination that results in progressive signal plans. An extension of the scheme to provide network-wide optimization of traffic signals is explained in the form of a two-layer scheme. Simulation experiments are performed with a newly developed simulator called STNS.
TL;DR: In this article, the ADVANCE Intelligent Transportation System operational test, in which more than 100 drivers used vehicles equipped with dynamic route guidance systems for 2-week periods, suggest that such drivers value real-time traffic information, and they want to incorporate their own knowledge and perspectives into the development of route plans, which they expect to be superior to those prepared by the navigation computer.
Abstract: Insights about the design of route guidance systems based on the needs and desires of drivers who are familiar with the travel network are provided. Results from the ADVANCE Intelligent Transportation System operational test, in which more than 100 drivers used vehicles equipped with dynamic route guidance systems for 2-week periods, suggest that such drivers value real-time traffic information, and they want to incorporate their own knowledge and perspectives into the development of route plans, which they expect to be superior to those prepared by the navigation computer. This suggests that future route guidance systems likely to be targeted at familiar drivers should be based on a sharing of tasks between computer and driver that takes greater advantage of driver knowledge than that considered in current designs. Specifically, the driver should be able to take more responsibility for route planning, with the computer responsible mainly for traffic congestion data acquisition, organization and storage, and evaluation of driver-defined routes.
01 May 1997
Journal Article•
TL;DR: In this paper, a series of studies investigating how Intelligent Transportation Systems (ITS) could be used to improve the integration of commercial vehicle operations (CVO) with governmental services and regulations within intermodal transportation management centers.
Abstract: This report documents findings from a series of studies investigating how Intelligent Transportation Systems (ITS) could be used to improve the integration of commercial vehicle operations (CVO) with governmental services and regulations within intermodal transportation management centers. After a summary of prior project research, the report gives a review of ITS/CVO technologies. This is followed by results of interviews and focus groups that reveal that trucking companies are willing to invest and participate in projects that possess four basic characteristics: 1) modest investment, 2) no new taxes or user fees, 3) promotes operating eficiency, customer service or safety, and 4) voluntary.
Journal Article•
TL;DR: This synthesis will be of interest to traffic engineers in federal, state, provincial, and local transportation agencies who are responsible for the design and operation of safe and efficient highway systems and consultants in the private sector who assist governmental clients in the application of changeable message sign (CMS) and other intelligent transportation systems (ITS) technology.
Abstract: This synthesis will be of interest to traffic engineers in federal, state, provincial, and local transportation agencies who are responsible for the design and operation of safe and efficient highway systems. It will also be useful to consulting traffic engineers, sign manufacturers, and vendors in the private sector who assist governmental clients in the application of changeable message sign (CMS) and other intelligent transportation systems (ITS) technology. It is an update of NCHRP Synthesis No. 61 (1979). It describes the various types of permanently mounted CMSs in use in the United States and Canada. This technology, also referred to as "variable message signs" or "motorist information displays", is in widespread use in North America. This report of the Transportation Research Board provides information on the various CMS types in use, their typical characteristics, including the technology types, the character (letters and numbers) types and size, and conspicuity. The synthesis presents a discussion on the types of messages used when there are no incidents. Other aspects, such as procurement, maintainability, and warranties are also discussed.
01 Dec 1997
TL;DR: This paper presents three case studies illustrating the importance and positive impacts of computer simulation in the development and evaluation of advanced traffic control systems.
Abstract: Traffic congestion has historically been regarded as a problem confined to major metropolitan areas. Over the years, the traffic problems that existed in densely developed urban areas began creeping into the suburbs as the work force migrated away from the traditional center city work pattern. Modem business operates at a feverish pace and is more mobile in nature, automobile technology advances have allowed more people to drive, and the commuting public has caused traffic congestion problems to appear even in small towns. Simply adding pavement to mitigate the traffic problems is neither adequate nor feasible. The Intelligent Transportation Systems (ITS) initiative was invoked by congress in 1991 to advance our traffic control systems by fostering development of Advanced Traffic Management Systems (ATMS). These technologies are designed to help move the motoring public more efficiently over the existing transportation system. Computer simulation has proved to be a vital adjunct to traditional traffic engineering analysis methods in hlly understanding the dynamics of traffic movement and control operations,. These simulation tools are critical in the development and evaluation of these new ideas, algorithms, and traffic control systems. This paper presents three case studies illustrating the importance and positive impacts of
01 Feb 1997
TL;DR: The FAST-TRAC project is a multi-year implementation and evaluation of an Intelligent Transportation System (ITS) in Southeastern Michigan and has two main components: an advanced traffic management system and two distinct in-vehicle advanced traveler information systems (ATIS), Ali-Scout and Tetra Star as discussed by the authors.
Abstract: The FAST-TRAC project is a multi-year implementation and evaluation of an Intelligent Transportation System (ITS) in Southeastern Michigan and has two main components: an advanced traffic-management system and two distinct in-vehicle advanced traveler information systems (ATIS), Ali-Scout and Tetra Star. The purpose of the User Perceptions and Behaviors element of FAST-TRAC is to understand how people use and what they think about the ATIS component of FAST-TRAC. The purpose of the present investigation was to compare not only how people use and what they think about these two specific systems and a third system using written instructions, but also compare performance and what people think about three distinct types of in-vehicle navigation-assistance systems when the systems are used concurrently under identical conditions on the road. Identical conditions were achieved by having triplets, or troikas, of people driving similar vehicles at the same time to the same destinations, while tracking all vehicles through satellite positioning. One person in the troika used Ali-Scout, one used Tetra Star, and one used written instructions. Driver familiarity with the area and traffic conditions were also investigated.
Journal Article•
TL;DR: In this article, the authors focus on longitudinal issues regarding modeling and control of vehicles in an Intelligent Transportation Systems (ITS) setting, and address the issue of vehicle control in an automated highway system, brake actuation and brake control.
Abstract: 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 the issue of switching from throttle to brake actuation.
20 Jun 1997
TL;DR: In this article, the authors focus on recent activities on automated highway systems at the California PATH (Automated Highway Systems Program) program, which was established by the California Department of Transportation (Caltrans) and the Institute of Transportation Studies (ITS) at the University of California at Berkeley to find solutions for California transportation problems.
Abstract: Summary form only given. The California PATH program was established in 1986 by the California Department of Transportation (Caltrans) and the Institute of Transportation Studies (ITS) at the University of California at Berkeley to conduct research on transportation systems, which include automated highway systems (AHS), to find solutions for California transportation problems such as congestion, mobility and productivity of system, safety, air quality and environment, energy consumption, cost effectiveness and regional and state wide economic health. This paper focuses on recent activities on AHS at the California PATH. AHS will include control problems from the vehicle level to the highway network level. The topics described cover PATH work at all levels, but an emphasis is given to control problems at the vehicle level, which will offer a number of challenging opportunities to control engineers.
01 Dec 1997
TL;DR: The research described in this report has the following objective: to describe the existing state of knowledge with respect to the interaction between automated, AVG supported vehicles and manually driven vehicles.
Abstract: Automated Vehicle Guidance (AVG) systems are systems in which driving tasks are supported or taken over partly or entirely by an automated system. The reported benefits of AVG systems involve improvements of road traffic performance, safety, and comfort. The research described in this report has the following objective: to describe the existing state of knowledge with respect to the interaction between automated, AVG supported vehicles and manually driven vehicles. The description focuses on the traffic effects of the interaction between automated and manually driven vehicles, and more precisely on the effect of this interaction on the maximum achievable capacity. (A)
01 Jan 1997
TL;DR: Whether making a lane available for 'intelligent' vehicles can increase the capacity of a bottleneck in the motorway network using the MICroscopic model for Simulation of Intelligent Cruise control (MIXIC) 1.3 is examined.
Abstract: Intelligent Cruise Control (ICC) is an in-car system that automatically maintains a specified speed, taking into account a minimal distance with respect to predecessors. This paper presents the results of a simulation study on the effects of a special lane for ICC vehicles on traffic flow on motorways. The microscopic traffic simulation model MIXIC was used to evaluate the traffic performance and traffic safety. Simulation results demonstrate that the introduction of a dedicated lane for ICC vehicles in the situation of lane drops can improve the traffic flow stability and the traffic throughput. For the covering abstract, see IRRD 490001.
Book•
01 Dec 1997
TL;DR: In this article, the authors look at privacy concerns related to Intelligent Transportation Systems (ITS) in an institutional context and propose conceptual frameworks to discuss the potential interactions between ITS technologies and the computer design profession, standards-setting bodies, marketing organizations, and government administrative agencies.
Abstract: This article looks at privacy concerns related to Intelligent Transportation Systems (ITS) in an institutional context. It offers conceptual frameworks to discuss the potential interactions between ITS technologies and the computer design profession, standards-setting bodies, marketing organizations, and government administrative agencies.
01 Jan 1997
TL;DR: As indicated throughout this volume, research and development on Advanced Vehicle Control Systems (AVCS) for Intelligent Transportation Systems (ITS) and Automated Highway Systems (AHS) to date has been primarily focused on passenger vehicles while commercial heavy vehicles such as heavy-duty freight trucks and commuter buses have been largely ignored.
Abstract: As indicated throughout this volume, research and development on Advanced Vehicle Control Systems (AVCS) for Intelligent Transportation Systems (ITS) and Automated Highway Systems (AHS) to date has been primarily focused on passenger vehicles,(1–3) while commercial heavy vehicles (CHVs) such as heavy-duty freight trucks (including tractor—trailer combinations) and commuter buses have been largely ignored. The obvious justification is that there are many more passenger vehicles on the road, and thus their automation will have the largest possible impact on the desired increase of highway traffic flow.
01 Jan 1997
TL;DR: The advent of the federal Automated Highway Systems (AHS) program, based on the guidance contained in ISTEA, has brought increased attention to the concept of highway automation within the past year.
Abstract: The advent of the federal Automated Highway Systems (AHS) program, based on the guidance contained in ISTEA, has brought increased attention to the concept of highway automation within the past year. The AHS Precursor Systems Analyses (PSA) projects and the initiation of work by the National Automated Highway System Consortium (NAHSC), which will conduct the Systems Definition Phase of the program, have provided opportunities for numerous people to think about AHS issues. Prior to these developments, AHS was generally regarded as something of a “fringe” issue in the world of Intelligent Transportation Systems, and only received serious research attention within the PATH Program.
TL;DR: This work uses ITS as an example of how system architecting methods, especially heuristic refinement, can be used to provide developmental guidance and to organize the process of architecture evaluation and selection.
Abstract: Intelligent transport systems (ITS) are members of an emerging class of systems which have highly distributed architectures and are equally distributed in their development, procurement, and management. Important characteristics of such systems include: (1) the lack of a client with ownership and developmental responsibility for the system, (2) considerable uncertainty in system purposes and a recognition that they will extensively evolve in unknown directions over the lifetime of the system, and (3) the need for extensive voluntary cooperation in their deployment and use. This work uses ITS as an example of how system architecting methods, especially heuristic refinement, can be used to provide developmental guidance and to organize the process of architecture evaluation and selection. In the particular case of ITS, these methods suggest an appropriate abstraction level for the architectural components, and means for combining deployment and architectural concerns.
TL;DR: The 1990s may well be remembered as the decade in which the idea of sustainability took hold in government, business, academia, and popular culture, and concerns with sustainability have entered policy discussions at various levels of government and sectors of the economy as mentioned in this paper.
Abstract: The 1990s may well be remembered as the decade in which the idea of sustainability took hold in government, business, academia, and popular culture. In the United States, concerns with sustainability have entered policy discussions at various levels of government and sectors of the economy. The application of the sustainability paradigm to transportation has coincided with the advent of intelligent transportation systems (ITS). ITS—the application of advanced technologies (e.g., computers, communications, advanced sensors) to the surface transportation system—is a major new advanced transportation technology initiative that has become a highly touted prospect for improving the nation's surface transportation system. ITS could have significant effects on the nation's environment, economy, and society, and this has prompted widespread research and speculation on the range of potential ITS impacts. It has also brought ITS into the sustainability debate, and controversy exists over whether ITS will facilitate...
01 Jan 1997
17 Sep 1997
TL;DR: This work describes a system able to recognize the V.L.P.P (Vehicle License Plate) of a car from an image of it, still under development and has many practical applications.
Abstract: In this work, we describe a system able to recognize the VLP (Vehicle License Plate) of a car from an image of it The system is still under development and has many practical applications As examples, we can mention: parking accounting systems, traffic monitoring and security systems of many kinds The system, at an experimental stage, is installed in a parking at the time of writing
TL;DR: A simulation experiment was conducted, using a prototype dual-task methodology developed to examine message content of VMS in work zones and to assess the effect of message type, display type, sign content, and repeated exposure to the signs on message comprehension and translation.