Transportation Information System Research Articles

Anonymous Vehicle Tracking for Real-Time Traffic Surveillance and Performance on Signalized Arterials

One of the fundamental requirements for facilitating implementation of any advanced transportation management and information system (ATMIS) is the development of a real-time traffic surveillance system able to produce reliable and accurate traffic performance measures. This study presents a new framework for anonymous vehicle tracking capable of tracing individual vehicles by the vehicle features. The core part of the proposed vehicle tracking method is a vehicle reidentification algorithm for signalized intersections based on inductive vehicle signatures. The new vehicle reidentification system consists of two major components: search space reduction and probabilistic pattern recognition. Not only real-time intersection performance but also intersection origin–destination information can be obtained as the algorithm’s basic output. A systematic simulation investigation was conducted of the performance and feasibility of anonymous vehicle tracking on signalized arterials using the Paramics simulation model. Extensive research experience with vehicle reidentification techniques on single roadway segments was the basis for investigating the performance that could be obtained from tracking individual vehicles across multiple detector stations. The findings of this study serve as a logical and necessary precursor to possible field implementation of vehicle reidentification techniques. The proposed anonymous vehicle tracking methodology with existing traffic surveillance infrastructure would be an invaluable tool for operating agencies in support of ATMIS strategies for congestion monitoring, adaptive traffic control, system evaluation, and provision of real-time traveler information.

Capacity Analysis of Urban Roads in Hong Kong

This paper presents a methodfor capacity analysis in urban roads using Hong Kong Annual Traffic Census (ATC) data. The proposed method aims to do away with the complicated methodologies and excessive adjustment factors which are obstacies in studying and determining the capacity threshold. This problem is especially relevant In Hong Kong, where, due to the complexity of the road geometry, traffic and control conditions makes It is extremely difficult to apply capacity analysis using complicated methodologies. A simplified level-of-service (LOS) methodology is proposed In this paper to carry out capacity analysis on urban roads using data obtained from the ATC which consists of hourly and daily trofficfiow variations. Subsequently, the spatiai anaiysis tool In geographic Information system (GIS) is used for LOS analysis. it was found that the methodology was able to determine the LOS Of urban roads by time and location conveniently and effectively. Extension Of the GIS for Transport Information System’s de...

SITS: a system for uniform intermodal freight transport information exchange

Abstract Intermodal transport chains consist of many actors and it is inherently difficult for a user to obtain an insight on the real progress of their transport at any moment or to interpret the consequences of a deviation. Based upon the results of a European Union financed project a user-friendly and technologically advanced method is proposed for trip information and data, transfer and analysis. This is based upon a “Transport Transaction data set”, which includes as a “Management Summary” all essential data for the transport: i.e. the information on the planned and real locations and times of the cargo. “Coupling” of several chains is foreseen. The data is represented as a eXtended Markup Language (XML) document. This approach is less error-prone than the common strategy of distributing individual status messages about transport events relying on each party to maintain an historical record and drawing conclusions from it. The proposed system for Simple Intermodal Tracking and Tracing Solutions (SITS), is a typical example of the information aggregation needed for the next generation of distributed transport information systems. The system presented here has been developed and demonstrated in pilot form.

Testing and Evaluating Alternative Algorithms for Location Referencing System Route Generation

Modeling the transportation network of roads and highways for data and information system implementations presents unique challenges. The foremost challenge is selecting a modeling methodology that is compatible with the needs and culture of the organization using it. The second challenge is implementing the model in a viable enterprise information system via a database. Transportation information systems must efficiently store network topology and geometry, as well as attributes, and they must be compatible with geographic information systems (GIS). This paper deals with the topological aspects of the highway network. In particular, it describes computing methodologies for generating location referencing system routes. The paper describes the link node referencing system used to build the routes and mentions an alternative approach using GIS. Various algorithms are presented and described, test case results are presented, the algorithms are compared, and evaluation criteria are defined.

Increasing the sophistication of access measurement in a rural healthcare study

This paper considers the problem of deriving realistic access measures between population demand and health service locations, in the context of a rural region of England. The paper reviews approaches used in earlier work by the authors and others, and considers new public transport information systems that are now becoming available. An application is presented which incorporates the modelling of both private and public transportation travel times for access to district general hospitals in Cornwall. This information has been assembled from published timetables in order to evaluate the use of more sophisticated access measures that might be used when such data becomes more generally available. The work is set within the context of an ongoing substantive research programme concerned with health outcomes in the rural South West of England.

Analytical Dynamic Traffic Assignment Model with Probabilistic Travel Times and Perceptions

Dynamic traffic assignment (DTA) has been a topic of substantial research during the past decade. Although DTA is gradually maturing, many aspects still need improvement, especially regarding its formulation and solution capabilities under the transportation environment affected by advanced transportation management and information systems. It is necessary to develop a set of DTA models to acknowledge the fact that the traffic network itself is probabilistic and uncertain, and different classes of travelers respond differently under an uncertain environment given different levels of traffic information. The aim of this research is to advance the state of the art in DTA modeling in the sense that the proposed model captures the travelers’ decision making among discrete choices in a probabilistic and uncertain environment, in which both probabilistic travel times and random perception errors that are specific to individual travelers are considered. Travelers’ route choices are assumed to be made with the objective of minimizing perceived disutilities at each time. These perceived disutilities depend on the distribution of the variable route travel times, the distribution of individual perception errors, and the individual traveler’s risk-taking nature at each time instant. The integrated DTA model is formulated through a variational inequality approach. Subsequently, the solution algorithm for the formulation is discussed, and experimental results are given to verify the correctness of solutions obtained.

Real-Time Traffic Measurement from Single Loop Inductive Signatures

Accurate traffic data acquisition is essential for effective traffic surveillance, which is the backbone of advanced transportation management and information systems (ATMIS). Inductive loop detectors (ILDs) are still widely used for traffic data collection in the United States and many other countries. Three fundamental traffic parameters—speed, volume, and occupancy—are obtainable via single or double (speed-trap) ILDs. Real-time knowledge of such traffic parameters typically is required for use in ATMIS from a single loop detector station, which is the most commonly used. However, vehicle speeds cannot be obtained directly. Hence, the ability to estimate vehicle speeds accurately from single loop detectors is of considerable interest. In addition, operating agencies report that conventional loop detectors are unable to achieve volume count accuracies of more than 90% to 95%. The improved derivation of fundamental real-time traffic parameters, such as speed, volume, occupancy, and vehicle class, from single loop detectors and inductive signatures is demonstrated.

CORBA-Based Distributed Geographic Information Systems for Transportation for Emergency Medical Services

With the advancement of intelligent transportation systems, current and future emergency medical services systems are and will be characterized by real-time response, specialization, and decentralization. To provide a real-time response of medical services, several components are essential, such as dispatching, routing, emergency facilities, and patient’s medical history. A common object request broker architecture (CORBA)–based geographic information system for a transportation framework is proposed for the dispatching and assignment of medical vehicles for emergency services via wireless communication. The framework combines distributed object computing, geographic information systems for transportation, and transportation models in a single system, which provides flexibility and interoperability among existing medical service systems. The framework uses the concept of distributed systems and capabilities of CORBA to design objects and dynamically update medical facilities’ information to relay up-to-date information to ambulances. A real roadway network is used in the numerical experiments to illustrate dynamic aspects of the proposed system.

ADVANCED TRANSPORTATION INFORMATION SYSTEMS: A COST-EFFECTIVE ALTERNATIVE FOR NETWORK CAPACITY EXPANSION?

As part of Advanced Transportation Information Systems (ATIS), route planning and guidance (RPG) services have been proposed for potential travel time savings and congestion reduction effects. This study extends previous studies by investigating their effect on consumer surplus and analyzing the tradeoff between network capacity expansions versus RPG services subsidy. Eventually, we analyze whether and to what extent can RPG services substitute network expansion. To answer these questions, this paper develops a mixed-equilibrium model for elastic travel demand and elastic market penetration of RPG services. Drivers are assumed to follow the stochastic user equilibrium conditions, with the drivers equipped with RPG services having lower travel time perception variations. This model is formulated as a nonlinear complementarity problem for exposition clarity and is solved as a variational inequality problem for efficiency, A numerical study is provided to demonstrate the approach.

Stochastic modeling and real-time prediction of vehicular lane-changing behavior

Time-varying lane-changing fractions and queue lengths are important lane traffic characteristics which may exhibit significant changes in the presence of a lane-blocking incident. This paper describes a stochastic system modeling approach to estimate time-varying lane-changing fractions and queue lengths for real-time incident management on surface streets. A discrete-time nonlinear stochastic model, which consists of recursive equations, measurement equations, and boundary constraints, is proposed to characterize inter-lane and intra-lane traffic state variables during incidents. To estimate lane-changing fractions and other state variables of the model, a recursive estimation algorithm is developed which primarily involves an extended Kalman filter, truncation, normalization, and a queue-updating procedure. Lane traffic counts are the sole input data used in this method. These data can be readily collected from conventional point detectors. The proposed model was calibrated using video-based data, then tested using simulated data from the TRAF-NETSIM simulation model, Version 5.0, as well as real video-based data sets. Preliminary test results indicate the feasibility of employing the proposed approach to estimate time-varying mandatory lane-changing fractions as well as queue lengths during incidents. The estimated lane-changing fractions and queue lengths can be used not only in better understanding the phenomena of incident-related inter-lane and intra-lane traffic characteristics, but also in developing real-time incident management technologies. Moreover, it is hoped that the results of this study might contribute to future research in related areas such as incident traffic prediction, incident-responsive traffic control and management, and automatic road congestion warning systems for further use in advanced transportation management and information systems.

Utilization of Information Technology to Enhance an Asphalt Pavement Condition Evaluation Program

Accurate and consistent pavement condition evaluations are essential for developing reliable pavement maintenance management systems. The Georgia Department of Transportation (GDOT) has developed a Pavement Condition Evaluation System (PACES) to meet this need. PACES has been used to evaluate the pavement conditions on the entire highway system in Georgia annually since 1986, and the results have been used for developing the maintenance plans. As a pan of the development of the Transportation Information System and the implementation of the Information Technology (IT) initiatives currently undertaken by the GDOT, a computerized pavement condition evaluation system (COPACES) was developed in 1998, which incorporated all the features of PACES. Through the utilization of IT, the management of the state's highway pavement maintenance program has been greatly enhanced by incorporating many additional features into COPACES. COPACES was successfully implemented in early 1999 for evaluating the pavement conditions for all asphalt pavements in the Georgia highway system. This paper presents the main features of COPACES and the implementation of this system by GDOT. Additional features that are currently under development for COPACES are also described in this paper.

Towards integrated traveller information

Traveller information provision has become a key government priority in the UK following the publication of its Transport White Paper in July 1998. Developments are already underway for the integration of information systems across different public transport modes and between public transport information systems covering different regions. The Highways Agency (which is responsible for managing the strategic road network in the UK) is also advancing in its development of information databases and systems for the motorist. This paper considers the prospect of providing travellers with multimodal information with integration of driver information with public transport information. If such integration can be achieved then travellers, and in particular drivers, have the prospect of being presented with comparable information on travel options across modes. An integrated information service has a great potential to inform and influence travel choices. The paper considers the issue of travel choices and the role that information can play particularly in the context of mode choice. The political (UK) and technological climate for information provision is outlined. The paper identifies issues that will need to be addressed to identify the requirements from, and potential benefits of, integrated information, and the obstacles and challenges likely to be faced in moving towards it. Driver reactions, in particular, to the prospect of integrated information provision are fundamental to the assessment of its potential importance and value.

Geographic information systems for transportation in perspective

The late 1980s saw the first widespread use of Geographic Information Systems (GIS) in transportation research and management. Due to the specific requirements of transportation applications and of the rather late adoption of this information technology in transportation, research has been directed toward enhancing existing GIS approaches to enable the full range of capabilities needed in transportation research and management. This paper places the concept of transportation GIS in the broader perspective of research in GIS and Geographic Information Science. The emphasis is placed on the requirements specific of the transportation domain of application of this emerging information technology as well as on core research challenges.

Improving Survivability of Intelligent Transportation Systems: Application-Level Intrusion Detection Case Study

Intelligent transportation systems (ITS) are deployed around the world to improve the safety and efficiency of surface transportation through the application of advanced information technology. However, ITS expose the transportation system to new vulnerabilities, making it imperative that those implementing such systems design them to be more survivable. The approaches most commonly used to increase the survivability of ITS are physical security, hardware redundancy, and software and data backups. An essential element of a survivable system that has not been adequately addressed is intrusion detection. Intrusion detection seeks to identify individuals who have gained unauthorized access to a system, as well as those with authorized access who are abusing the system. Described is the importance of robust intrusion detection for ITS (and other transportation information systems). The state of the practice in intrusion detection is summarized, and a case study is presented that investigates the development of an intrusion detection system (IDS) conceptual design for an essential element of ITS, electronic toll collection. Through the case study, the researchers found that intrusion detection at the application level could significantly improve the overall surviv-ability of ITS. From this finding, it is clear that there is a need to commit resources to developing application level IDS for the wide range of ITS. Given the importance of surface transportation to a region’s economy and the potential vulnerabilities introduced by ITS, it is imperative that further work be conducted to increase the survivability of ITS.

Promoting More Efficient Use of Urban Areas in Developing Countries: An Alternative

Planners can apply a relatively simple and user-friendly tool to control the expansion of urban areas in developing countries. This tool, presented here, is based on a traditional accessibility index, which may be taken as a measure of urban development. The entire process of construction and analysis of the networks based on the accessibility index was carried out using a geographic information system for transportation (GIS-T). The tool has been tested in São Carlos, a medium-sized Brazilian city, in which the effects of some proposed real estate developments on the accessibility patterns have been studied. The results of this application show that the tool is suitable for selecting the best site for a new development among many alternatives, promoting more efficient use of the urban area.

Context-sensitive spoken dialogue processing with the DOP model

We show how the DOP model can be used for fast and robust context-sensitive processing of spoken input in a practical spoken dialogue system called OVIS. OVIS (Openbaar Vervoer Informatie Systeem) – ‘Public Transport Information System’, is a Dutch spoken language information system which operates over ordinary telephone lines. The prototype system is the immediate goal of the NWO Priority Programme ‘Language and Speech Technology’. In this paper, we extend the original Data-Oriented Parsing (DOP) model to context-sensitive interpretation of spoken input. The system we describe uses the OVIS corpus (which consists of 10,000 trees enriched with compositional semantics) to compute from an input word-graph the best utterance together with its meaning. Dialogue context is taken into account by dividing up the OVIS corpus into context-dependent subcorpora. Each system question triggers a subcorpus by which the user answer is analysed and interpreted. Our experiments indicate that the context-sensitive DOP model obtains better accuracy than the original model, allowing for fast and robust processing of spoken input.

Potential Contributions of Spatial Analysis to Geographic Information Systems for Transportation (GIS‐T)

Geographic information systems (GIS) are having tremendous impacts on many scientific and application domains. The traditional subfield of spatial analysis is witnessing a major resurgence and enhancement due to GIS and geographical information science (GISci), an interdisciplinary field focusing on the theory and methodology underlying GIS software. The interdisciplinary field of geographic information systems for transportation (GIS‐T) has emerged to focus on the role of GIS in transportaton analysis and planning. This paper suggests the benefits of closer linkages between spatial analysis, GISci, and transportation through a focused review of spatial analytical issues and their potential contributions to GIS‐T. Specifically, this paper reviews the following issues: (i) modifiable areal units; (ii) boundary problems and spatial sampling; (iii) spatial dependence and spatial heterogeneity; and (iv) alternative representations of geographic environments. The discussion highlights the general issues as well as identifies their specific relevance to GIS‐T. In addition, this paper identifies some emerging tools from GISci that can address these spatial analytical issues in GIS‐T.

Use of vehicle signature analysis and lexicographic optimization for vehicle reidentification on freeways

The vehicle reidentification problem is the task of matching a vehicle detected at one location with the same vehicle detected at another location from a feasible set of candidate vehicles detected at the other location. This paper formulates and solves the vehicle reidentification problem as a lexicographic optimization problem. Lexicographic optimization is a preemptive multi-objective formulation, and this lexicographic optimization formulation combines lexicographic goal programming, classification, and Bayesian analysis techniques. The solution of the vehicle reidentification problem has the potential to yield reliable section measures such as travel times and densities, and enables the measurement of partial dynamic origin/destination demands. Implementation of this approach using conventional surveillance infrastructure permits the development of new algorithms for ATMIS (Advanced Transportation Management and Information Systems). Freeway inductive loop data from SR-24 in Lafayette, California, demonstrates that robust results can be obtained under different traffic flow conditions.

Problems of Cartographic Design in Geographic Information Systems for Transportation

Geographic information systems for transportation (GIS-T) seek to integrate the geospatial approach of GIS and the tabular approach of conventional transportation analysis. GIS-T deals with such topics as network analysis, linear reference systems, travel demand modeling, and intelligent transportation systems. Conventional cartographic treatment of route features is reviewed in the context of the mapping challenges introduced by GIS-T. Problems in the visualization of complex linear data are identified and examined as cartographic design issues. Cartographic requirements are specified for mapping route-based data and basic design issues are identified. The representation of complex route-based data layers is posed as an undeveloped specialty of cartographic design. Some of the issues involved in developing such fundamental principles are summarized and potential avenues of research are suggested.

Gauging the returns on investments in Competitive Intelligence: A three-step analysis for executive decision makers

Competitive intelligence (CI) can support complex decisions and generate tremendously powerful momentum in the execution of corporate strategy. Increasingly, diverse groups of companies are relying on intelligence to supplement their business decisions. Nearly all that do, however, face difficulties forecasting possible returns on their investments. Many decision-makers are, therefore, disinclined to invest because the risks are perceived as being greater than the rewards. This article presents a three-step valuation process that will help decision makers more fully understand the potential investment and its potential returns. The first step involves considering the factors that drive CI cash flows, the second requires estimating the values of those variables, and the third entails judging whether or not the investment makes sense. The issue is brought into focus by illustrating the corporate planning activities of a transportation information systems manufacturer. The company was at first unclear about their information needs and priorities not unusual for many competitors. The decision-maker was walked-through the three-step analysis and was shown the value of making investments in specific areas of CI. The analysis will clarify some of the issues surrounding the choice to invest in CI. Unfortunately, a working model cannot be standardized because of the particularity of each situation as well as the great diversity between situations. Executive decision makers must therefore take the steps to proactively identify, understand, and measure the germane factors that impinge on the investment's success. In no uncertain terms, such a demanding decision making process will bring about more practicable results. © 1999 John Wiley & Sons, Inc.