Showing papers on "Intelligent transportation system published in 1996"

Traffic control systems handbook

Abstract: This "Traffic Control Systems Handbook" updates the 1985 edition (FHWA-IP-85-11; TRIS 00475445) and broadens the scope to include Intelligent Transportation Systems (ITS) technology and concepts. The Handbook recommends decision-making processes in selection, implementation and operations of a traffic control system and describes ITS plans and programs. The "Traffic Control Systems Handbook": serves as a basic reference in planning, designing and implementing effective traffic control systems; provides an updated compendium of existing traffic control technology for the advanced designer and user; describes existing and evolving traffic control system technology; and aids understanding and facilitates training in the traffic control system field. The Handbook targets: administrators; traffic engineers; transportation planners; and students. In addition to summarizing the state-of-the-practice, chapters include "A Look to the Future" section where appropriate. In this way, the material separates proven technology from systems and elements currently under development.

Modal Emissions Modeling: A Physical Approach

Abstract: Mobile source emission models currently used by state and federal agencies (e.g., Environmental Protection Agency's MOBILE and California Air Resources Board's EMFAC) are often inadequate for analyzing the emissions impact of various transportation control measures, intelligent transportation systems, alternative fuel vehicles, and more sophisticated inspection/maintenance programs contained in most state air quality management plans. These emission models are based on the assumption that vehicle running exhaust emissions can be represented as integrated values for a specific driving cycle, and then later adjusted by speed correction factors. What is needed in addition to these "regional-type" mobile source models is an emissions model that considers at a more fundamental level the modal operation of a vehicle (i.e., emissions that directly relate to vehicle operating modes such as idle, steady-state cruise, various levels of acceleration/deceleration, and so forth). A new modal-emissions modeling approac...

Travel demand model system for the information era

Abstract: The emergence of new information technologies and recent advances in existing technologies have provided new dimensions for travel demand decisions. In this paper we propose a comprehensive travel demand modeling framework to identify and model the urban development decisions of firms and developers and the mobility, activity and travel decisions of individuals and households, and to develop a system of models that can be used by decision makers and planners to evaluate the effects of changes in the transportation system and development of information technologies (e.g. various tele-commuting, tele-services and Intelligent Transportation Systems). The implementation of an operational model system based on this framework is envisioned as an incremental process starting with the current “best practice” of disaggregate travel demand model systems. To this end, we present an activity-based model system as the first stage in the development of an operational model system.

Traffic dynamics: method for estimating freeway travel times in real time from flow measurements

Abstract: This paper presents a method for estimating freeway travel times in real time directly from flow measurements, which is desirable for present and future Intelligent Vehicle-Highway Systems (IVHS) applications. An inductive modeling approach adapted here is based on stochastic queuing theory and the principle of conservation of vehicles. The analytical expression for link travel times satisfies traffic dynamics where the new form of the conservation of vehicles has been derived under generalized traffic conditions. A computer program has been developed to implement the algorithm. Analysis results show that the estimates have good agreement with empirical data measured at 30-s intervals. This methodology has potential applicable to automatic traffic control and automatic incident detection.

Visual tracking for intelligent vehicle-highway systems

Abstract: The complexity and congestion of current transportation systems often produce traffic situations that jeopardize the safety of the people involved. These situations vary from maintaining a safe distance behind a leading vehicle to safely allowing a pedestrian to cross a busy street. Environmental sensing plays a critical role in virtually all of these situations. Of the sensors available, vision sensors provide information that is richer and more complete than other sensors, making them a logical choice for a multisensor transportation system. We propose robust detection and tracking techniques for intelligent vehicle-highway applications where computer vision plays a crucial role. In particular, we demonstrate that the controlled active vision framework can be utilized to provide a visual tracking modality to a traffic advisory system in order to increase the overall safety margin in a variety of common traffic situations. We have selected two application examples, vehicle tracking and pedestrian tracking, to demonstrate that the framework can provide precisely the type of information required to effectively manage the given traffic situation.

Route choice and advanced traveler information systems on a capacitated and dynamic network

Abstract: Much of the push behind Intelligent Transportation Systems (ITS) has come from the hope that providing travelers with better information will result in reduced travel time and traffic congestion. Phase 1 of the United States' IVHS National System Architecture project, for instance, made ATIS (Advanced Traveler Information Systems) the centerpiece of its benefits evaluation, and ATIS has been the subject of numerous traffic simulation studies. The objective of this paper is to examine the ‘informational’ assumptions embedded in traffic simulations, and to assess how these assumptions affect simulation results. Most importantly, this paper examines the hypothesis that increasing market penetration can lead to a decrement in network performance. The paper proves, for a simple parallel network, that increasing the market penetration of accurate information cannot harm network performance. For this same network, the paper shows that increasing the penetration of instantaneous travel time estimates might degrade network performance. The paper also asserts that the existence, or non-existence, of an optimal market penetration is moot. The suggestion is that ATIS should not be viewed as a strategy for achieving system optimal traffic distributions. ATIS should instead be viewed first as a service to the public, to improve their confidence and comfort in using the system, and second as a means for steering traffic away from dis-equilibrium behavior and toward user optima that utilize alternate routes where feasible.

Dynamic Decision Making for Commercial Fleet Operations Using Real-Time Information

Abstract: The application of intelligent transportation system technologies to freight mobility requires dynamic decision-making techniques for commercial fleet operations, using real-time information. Recognizing the productivity-enhancing operational changes possible using real-time information about vehicle locations and demands coupled with constant communication between dispatchers and drivers, a general carrier fleet management system is described. The system features dynamic dispatching, load acceptance, and pricing strategies. A simulation framework is developed to evaluate the performance of alternative load acceptance and assignment strategies using real-time information. Real-time decision making for fleet operations involves balancing a complicated set of often conflicting objectives. The simulation framework provides a means for exploring the trade-offs between these objectives. Results suggest that reductions in cost and improvements in service quality should result from the use of dynamic dispatching...

Intelligent transportation systems: an economic and environmental policy assessment

Abstract: This paper discusses the congestion relief and environmental impacts expected of Intelligent Transportation Systems (ITS) based on a qualitative assessment of the incentives generated. It uses theoretical and empirical results from the literature to evaluate the private and externality impacts of Advanced Traveler Information Systems (ATIS), Automated Highway Systems (AHS) and Intelligent Transit Systems and discusses the appropriate role of the public sector in their development based on these impacts. It is argued that although ITS are intended to improve system efficiency, the technologies may, in fact, exacerbate the existing, economic inefficiencies in the surface transportation system and that policies to correct these inefficiencies become all the more crucial as we consider implementation of ITS. Several policies that target environmental externalities are discussed as possible complements to ITS.

Multiple-Interval Freeway Traffic Flow Forecasting:

Abstract: Freeway traffic flow forecasting will play an important role in intelligent transportation systems. The TRB Committee on Freeway Operations has included freeway flow forecasting in its 1995 research program. Much of the past research in traffic flow forecasting has addressed short-term, single-interval predictions. Such limited forecasting models will not support the development of the longer-term operational strategies needed for such events as hazardous material incidents. A multipleinterval freeway traffic flow forecasting model has been developed that predicts traffic volumes in 15-min intervals for several hours into the future. The nonparametric regression modeling technique was chosen for the multiple-interval freeway traffic flow forecasting problem. The technique possesses a number of attractive qualities for traffic forecasting. It is intuitive and uses a data base of past conditions to generate forecasts. It can also be implemented as a generic algorithm and is easily calibrated at field locati...

Integration Of Probe Vehicle And Induction Loop Data: Estimation Of Travel Times And Automatic Incident Detection

Abstract: This research investigates methodologies for fusing and further processing real-time road traffic data collected by probe vehicles and induction loop detectors in order to obtain relevant traffic information that is essential for effective deployment of Advanced Traffic Management Information Systems (ATMIS). Methods for estimating travel times and performing automatic incident detection for ATMIS based on induction loop or probe vehicle data are developed. By properly incorporating additional traffic data from the other source the performance of the developed methods is shown to improve.

Its data fusion

Abstract: This project has accomplished three significant tasks. First, a state-of-the-art literature review has provided an organizational framework for categorizing the various data fusion projects that have been conducted to date. A popular typology was discussed which situates data fusion technologies in one of three levels, depending on the degree to which sensor data is correlated to provide users with meaningful transit recommendations. The trade-offs that accompany higher-level data fusion efforts--in terms of computing power and memory requirements--were noted. The advantages of multiple-sensor data fusion projects in terms of cost, accuracy, and reliability were also discussed and contrasts were drawn with the traditional deployment of highly accurate, single sensors. Specific techniques of data fusion were described and their possible applications to Intelligent Transportation System (ITS) projects were explored. In fact, this report is one of the first to consider how data fusion technology might be productively applied to the needs of transportation management. A second major component of this report is the description provided of a local data fusion application. This project employs data fusion techniques to correlate input from multiple highway sensors and generate reliable traffic predictions. The resulting information can be displayed for use by commuters as they choose from among various transit options. The architecture of this data fusion system is described in detail. The third component of the project was to create a statistically based algorithm to estimate speed from volume and occupancy measurements. The algorithm presented explicitly accounts for the statistics of the problem and provides a robustness test for the speed estimate.

Telematics and Transport Behaviour

Abstract: This book offers both a behavioural framework for analyzing transport telematics and brings together a series of studies on transport telematics and its implications for spatial behaviour of users in different fields (e.g., private car drivers, users of public transport, fleet operators). The book aims to offer a state of the art survey of many applications of transport telematics, with a particular view on behavioural and policy responses. It is unique in that for the first time in the recent history of telematics, a comprehensive analysis is given of the fruits of this new technology. Hence, it contains many case studies on human behaviour and transport telematics. Most studies presented in this book are the offspring of the European DRIVE programme on transport telematics. The empirical results have in particular been achieved in the framework of BATT (Behaviour and Advanced Transport Telematics) and MARTA (Monitoring Attitudes towards Road Transport Automation) projects in the DRIVE programme.

Case-based reasoning: A planning tool for intelligent transportation systems

Abstract: This paper develops a Case-Based Reasoning (CBR) methodology for PLANiTS (Planning and Analysis Integration for Intelligent Transportation Systems). To address a current transportation planning situation, CBR presents similar historical cases. Specifically, it estimates the impacts of proposed transportation improvement actions, including Intelligent Transportation Systems, based on previous experiences with similar actions. In this paper, a hierarchical structure for representing historical cases is developed. All historical cases consist of transportation improvement actions, performance measures and environments defined in terms of their spatial, temporal and user/traveler dimensions. In addition, cases contain information about lessons learnt such as inferences regarding their success or failure, prescriptions and case quality. Information about historical cases can be synthesized. Specifically, the reasoner contains mechanisms for 1. (a) matching at various levels of stringency, 2. (b) ranking with alternative distance and weight measures 3. (c) analyzing similar past cases with statistical operations. Also discussed are the limitations of CBR applications to transportation planning. Overall, the structure for the CBR is flexible and incorporates different stakeholder preferences for alternative transportation improvement actions and evaluation criteria. Further, the application of CBR to transportation planning, discussed in this paper, formalizes the use of case knowledge in transportation. This can lead to improving the transportation planning process.

Experimental research on inter-vehicle communication using infrared rays

Abstract: A prototype inter-vehicle communication system for intelligent transport systems, using infrared rays, has been developed and successfully demonstrated. In this study, our efforts have mainly focused on protocol development. For inter-vehicle communication, a very quick transmission cycle, high adaptability to vehicle formation change and high data reliability are required. In this paper, we have proposed new communication protocol which satisfies these requirements. In the experiment, four test vehicles equipped with the prototype system were run on a test track. Actual communication was carried out with vehicles running in various situations successfully and status maps for adjacent vehicles were obtained from the received data.

Smart cars, smart roads

Abstract: This article discusses how freeway congestion is expected to quadruple by the year 2005. It describes how the Intelligent Transportation Society of America (ITS America) is at the forefront of devising solutions. Several individual firms are profiled.

Traffic queue length measurement using an image processing sensor

Abstract: As social economic activities grow, an advanced traffic control system corresponding to the changes of road traffic circumstances becomes an urgent matter. And traffic information service or the profit convenience for travelers and commodity distribution are also needed. In April 1993 under such a situation, the synthetic and epoch making traffic management system, Universal Traffic Management Society of Japan (UTMS), was established. Among the purposes of UTMS, especially the Integrated Traffic Management System (ITCS), is the development of a more optimum signal control algorithm which can correspond to the traffic situation that changes at every moment. To realize this, an advanced sensor which can collect more precise and more detailed traffic flow information is needed. In September 1993, UTMS established a new working group, the purpose of which was research and development of an image sensor which provides useful traffic flow information for traffic signal control to realize the ITCS. In this working group the authors started examining a specification of the image sensor. This image sensor processes images received from the ITV camera installed above the approach lane at a traffic signal intersection, and can directly measure queue and delay length up to 150m, as well as the number of passed vehicles, speed, vehicle type and vehicle existence in a 30m area. The authors have developed new measurement algorithms and new hardware, and succeeded in the development of a new image sensor, SPatial Image processing Traffic flow Sensor (SPITS), which satisfies this specification. While the function of direct measurement of queue and delay length is the advantage of an image sensor, it is hard to measure them precisely in the distance from the camera position because of poor visibility. SPITS has succeeded in enabling the measurement of queue and delay length precisely, even at a distance, with a sophisticated method and in real time processing. SPITS has been evaluated by field tests. The experimental results show that SPITS has achieved accurate measurement within 10% error of maximum queue length under various conditions (day, night, twilight, rain etc). and confirm that SPITS is able to provide useful traffic flow information for ITCS. In this paper, the authors will show these results as well as the queue delay length measurement method used, and hardware configuration.

Converging Infrastructures: Intelligent Transportation and the National Information Infrastructure

Abstract: From the Publisher: This collection explores the opportunities for and possible implications of coordination between two of the major pieces of emerging infrastructure in the United States: Intelligent Transportation Systems (ITS) and the National Information Infrastructure (NII). Based on a recent workshop that was sponsored by the U.S. Department of Transportation, MIT, and Harvard, Converging Infrastructures frames the programmatic, organizational, and technical issues involved.

The national advanced driving simulator: potential applications to its and ahs research

Abstract: In announcing the new Operation TimeSaver program in January of this year to the Transportation Research Board, DOT Secretary Federico Pena stated: "I want 75 of our largest metropolitan areas with a complete Intelligent Transportation Infrastructure in 10 years." The goal of this system is to reduce daily travel time by 15%. The upcoming deployment of various Intelligent Transportation Systems (ITS) and Automated Highway System (AHS) technologies will require major adjustments in the habits of drivers. Implementers of ITS technology must ensure that their systems are safe and lead to real improvements in traffic efficiency. These systems cannot cause excessive driver workload or remove his/her sense of "control" of the vehicle. A highly realistic driving simulator provides a powerful method of evaluating in-vehicle ITS technology in complex situations.

Review of the potential benefits of road transport telematics

Abstract: This study presents an examination of the potential benefits of a wide range of telematics applications. It looked at scenarios for 36 different applications, covering inter-urban and urban traffic management and control, monitoring and enforcement, public transport trip planning, driver information, navigation and guidance, freight and fleet management, the automated vehicle and highway, and applications for vulnerable road users. The study also developed a test scenario and tried to build a cost- benefit calculation for most applications

A formulation and solution algorithm for a multi-class dynamic traffic assignment problem

Abstract: Dynamic traffic assignment (DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution capabilities. In order to model the impact of Advanced Transportation Management and Information Systems (ATMIS), especially route guidance and other information provision systems, it is necessary to develop a set of multi-class traffic models to acknowledge the fact that there are different classes of users of the transportation system, and that they respond differently to traffic information. At least, the model should be able to differentiate travelers or vehicles who receive real-time traffic information versus those who don't. This paper aims to advance the state-of-the-art in DTA modeling. In this paper, an analytical approach is developed to model multiple classes of users of the transportation system. It is a step forward of the long-term efforts in analytical DTA modeling, which distinguishes itself from simulation-based DTA models. Specifically, the users are divided into three classes: (i) fixed route travelers; (ii) stochastic dynamic user-optimal (SDUO); (iii) dynamic user-optimal (DUO). The property of each class is defined and integrated into one modeling framework through a Variational Inequality (VI) approach. Subsequently, a solution algorithm for the formulation is discussed. This algorithm uses a combination of various solution techniques, such as relaxation, Frank-Wolfe and Method of Successive Averages (MSA). It is applied to four scenarios to verify the correctiveness of the solutions obtained. (A) For the covering abstract see IRRD 886400.

Systems and methods employing video combining for intelligent transportation applications

Abstract: A multicamera surveillance system (300) connects video surveillance cameras (104) to a video bridge (310). One or more users (108) in the same or different locations may obtain video from one or more video cameras from this bridge, without having a direct connection to the video cameras. The invention may use graphic combining techniques so that the video inputs may be superimposed on a graphic image, such as a map. The video surveillance cameras may be pannable electronic cameras which provide a user selectable panorama of the scene under surveillance. The inventive system provides a video surveillance system which is simple to understand and use. It also provides a centralized video bridge which may be used to provide a number of monitoring stations to independently view video inputs of interest. Thus, state and local police, EMS dispatch, fire stations, trucking companies, commuters, or any other interested party may be able to view locations of interest using relatively inexpensive equipment, such as a computer and joystick.

Studies of potential intelligent transportation systems benefits using traffic simulation modeling

Abstract: This report documents six studies performed by Mitretek Systems to analyze potential benefits of Intelligent Transportation Systems (ITS) deployment. The studies were conducted in support of the U.S. Department of Transportation Joint Program Office on ITS and the Federal Highway Administration (FHWA). The studies explore the operation and benefits of ITS services in three areas: Advanced Traveler Information Systems (ATIS), Advanced Traffic Management Systems (ATMS), and Commercial Vehicle Operations (CVO). The studies use simulation models to quantify the benefits of ITS deployment in typical urban and inter-urban scenarios and to study key sensitivities.

Planning, Implementation, and Evaluation of OmniRide Demand-Driven Transit Operations: Feeder and Flex-Route Services

Abstract: Information about the Potomac and Rappahannock Transportation Commission operational test is presented. The test focuses on service planning for the local flex-route transit services and the flag-stop commuter-rail feeder services, as well as their start-ups. Although the intelligent transportation system (ITS) operational test involves the application of automated vehicle location and real-time order-taking, scheduling, and dispatching of software, the planning and start-up operations of the non-ITS-enhanced phase of the flex-route and feeder services are addressed.

Dynamic dispatching strategies under real-time information for carrier fleet management

Abstract: Dynamic dispatching is an important aspect of Commercial Vehicle Operations (CVO) applications of ITS technologies. This research identifies and tests ways in which operations should change in order to take full advantage of real-time information on vehicle locations and demands. In the context of truckload trucking operations, flexible assignment strategies are identified. Under idealized conditions the fraction of the fleet available to provide service to time sensitive loads or to loads that would more efficiently be served immediately is estimated. The authors explore through simulation the benefits of a real-time dispatching strategy that incorporates diversion of en-route vehicles. (A) For the covering abstract see IRRD 886400.