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Intelligent transport systems: emerging technologies and methods in transportation and traffic
Transportation Research Part C 12 (2004) 167–169 www.elsevier.com/locate/trc
Editorial
Intelligent transport systems: emerging technologies and methods in transportation and traffic
The links between new transport technologies and transport theories grow more strongly all the time. The possibilities opened up by the development and implementation of new technologies open the door to new developments in theory––sometimes by facilitating the development of the theory, e.g. through new possibilities to measure and model transport phenomena, sometimes by requiring the development of theory to explain the uptake of the technology or to better understand transport systems operations. In conjunction with the 15th International Symposium on Transportation and Traffic Theory (ISTTT15)––see Taylor (2002), held at the University of South Australia in July 2002, an international workshop was held to explore these linkages between new theory and new technology, and to consider certain emerging technologies that will have considerable impacts on transport planning theory and practice in the near future. The seven papers presented in this special issue of Transportation Research C are the outputs of that international workshop on ÔIntelligent Transport Systems: emerging technologies and methods in transportation and trafficÕ. Whilst the papers tend to focus on new implementations of Intelligent Transport Systems (ITS) technologies, their applications cover a wide range and show many facets of transport systems planning and operations where new technologies are making profound impacts, for both personal travel and for freight travel. The papers include considerations of new methods to collect detailed travel survey information by monitoring the locations and movements of experimental subjects, new methods for considering driver route choice and the impacts of risk taking behaviours, new applications for dynamic routing and scheduling of freight vehicles in congested urban areas using real-time traffic information systems, new applications to the monitoring the usage of multimodal urban transit services, and new conceptual developments for the operation of traffic control systems, such as traffic signals, using automated driving technologies to enhance intersection efficiency and throughput. The paper by Yin, Lam and Ieda sets the scene by demonstrating some means by which ITS technologies can improve traffic congestion levels in urban road networks. Recognising the significance of the reliability of travel times in route choice and departure time choice decisions by individuals and the impacts that Advanced Traveller Information Systems (ATIS) may play 0968-090X/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.trc.2004.07.001
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Editorial / Transportation Research Part C 12 (2004) 167–169
in these decisions, the authors studied the effects of different risk taking behaviours by commuters. They describe the development of a model that considers departure time and route choices under network conditions where different levels of congestion may exist, some of which is non-recurrent (or Ôincident-basedÕ) congestion. Commuters are then assumed to make their decisions on the basis of a minimum perceived travel disutility, which can be influenced through the provision of advice from an ATIS. Similarly Yang and Huang also consider the impacts of ATIS, but their focus is on the evolution of market penetration of ATIS. Previous research in the field had indicated that the benefits of the use of ATIS increase initially with market penetration, as the numbers of users grow from small initial beginnings, but then may decline at penetration levels above some optimal amount and may even yield negative benefit (increased total travel time) in some situations, due to over-reactions by ATIS users. This has led to a general transport policy conclusion that it is only necessary or desirable to equip a limited proportion of vehicles with ATIS. This paper takes a different view, attempting to find an optimal strategy for the market penetration of ATIS that will preserve the benefits of the technology through differential pricing for new ATIS users on the basis of current levels of penetration. In this way net information benefit and heterogeneity in driver behaviour are incorporated as important factors affecting the growth of ATIS usage. The authors discuss the identification of optimal levels of ATIS market penetration in different networks and the service charges that may be levied to achieve the optimum levels. RidwanÕs paper is also concerned with driver route choice decisions. He introduces a fuzzy preference based model of route choice, which can account for drivers who do not necessarily attempt to minimise travel time or cost in their route choice decisions. The fuzzy preference modelling approach considers uncertainty of decision making by individual travellers in a dynamic traffic system, and can be used to support ATIS project implementations. ATIS designed specifically for urban freight operations form a basis for the research described by Taniguchi and Shimamoto. Their paper presents a dynamic vehicle routing and scheduling model that can incorporate real time traffic information using variable travel times in a road network, using dynamic traffic simulation to update travel times. An application of their model to a test network of some complexity indicates that the total costs of freight operations and (in many cases) the total hours of travel of freight vehicles in the network could be substantially decreased through the availability of dynamic travel time advice. This suggests that dynamic scheduling and routing can provide benefits to freight operators, through reducing their costs of operation, and the community, through amelioration of traffic congestion in an urban area. Lo, Yip and Wan move the emphasis of emerging technologies from road-based transport to multi-modal urban public transport systems. Their particular interest is in the study of multi-modal trips, where a traveller uses more that one public mode and/or service to complete a given journey. In an environment with competing private sector operators of transit services and different fare structures and systems, modelling multi-modal trips is complex. The paper presents a nested logit modelling framework that can be used to examine the effects of fare competition on traveller behaviour, operator profitability and network performance. The authors use a case study of the ground transportation system connecting Hong KongÕs international airport to the downtown areas. Asakura and Hato consider the monitoring of pedestrian movements in urban areas, using a variety of alternative tracking technologies. Their paper demonstrates fundamental concepts
Editorial / Transportation Research Part C 12 (2004) 167–169
169
and methods for the use of mobile communication instruments such as cellular telephones for tracking the movements of individual subjects. In addition, they note the requirement to study travel behaviour, for which location information alone is insufficient. To overcome this problem, the authors developed an algorithm to provide various trip attributes for each point recorded in the location positioning data. The validity of the algorithm and the accuracy of measurement are then assessed for a sample of 100 individuals surveyed using the combined data logging system. The final paper in the special issue, that by Clement, Taylor and Yue, describes and models the performance of a conceptual ITS system for the automatic progression of vehicles through a signalised intersection, under the automatic control of in-vehicle and roadside infrastructure. The basic principle is the notion that the queue of vehicles assembled at a red signal can be moved simultaneously as a single block (platoon) once the signal aspect switches to green. Once clear of the intersection, the vehicles in the platoon are progressively released back to individual driver control. The advantage of this automated platoon advancement strategy may be seen in increased throughput and decreased delays for approach lanes at signalised intersections. This technology could offer the opportunities for substantial increases in the capacities of existing intersections or for the alternative use of existing road space (e.g. for increased pedestrian facilities or exclusive bus lanes and transit priority) at intersections whilst maintaining current capacity levels. The special issue should make an informative and creative contribution to research and debate on new ITS implementations for improved traffic and transport planning and operations.
Reference Taylor, M.A.P. (Ed.), 2002. Transportation and Traffic Theory in the 21st Century. Pergamon, Oxford.
Michael A.P. Taylor Transport Systems Centre University of South Australia Adelaide SA 5000 Australia E-mail address: [email protected]
Editorial
Intelligent transport systems: emerging technologies and methods in transportation and traffic
The links between new transport technologies and transport theories grow more strongly all the time. The possibilities opened up by the development and implementation of new technologies open the door to new developments in theory––sometimes by facilitating the development of the theory, e.g. through new possibilities to measure and model transport phenomena, sometimes by requiring the development of theory to explain the uptake of the technology or to better understand transport systems operations. In conjunction with the 15th International Symposium on Transportation and Traffic Theory (ISTTT15)––see Taylor (2002), held at the University of South Australia in July 2002, an international workshop was held to explore these linkages between new theory and new technology, and to consider certain emerging technologies that will have considerable impacts on transport planning theory and practice in the near future. The seven papers presented in this special issue of Transportation Research C are the outputs of that international workshop on ÔIntelligent Transport Systems: emerging technologies and methods in transportation and trafficÕ. Whilst the papers tend to focus on new implementations of Intelligent Transport Systems (ITS) technologies, their applications cover a wide range and show many facets of transport systems planning and operations where new technologies are making profound impacts, for both personal travel and for freight travel. The papers include considerations of new methods to collect detailed travel survey information by monitoring the locations and movements of experimental subjects, new methods for considering driver route choice and the impacts of risk taking behaviours, new applications for dynamic routing and scheduling of freight vehicles in congested urban areas using real-time traffic information systems, new applications to the monitoring the usage of multimodal urban transit services, and new conceptual developments for the operation of traffic control systems, such as traffic signals, using automated driving technologies to enhance intersection efficiency and throughput. The paper by Yin, Lam and Ieda sets the scene by demonstrating some means by which ITS technologies can improve traffic congestion levels in urban road networks. Recognising the significance of the reliability of travel times in route choice and departure time choice decisions by individuals and the impacts that Advanced Traveller Information Systems (ATIS) may play 0968-090X/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.trc.2004.07.001
168
Editorial / Transportation Research Part C 12 (2004) 167–169
in these decisions, the authors studied the effects of different risk taking behaviours by commuters. They describe the development of a model that considers departure time and route choices under network conditions where different levels of congestion may exist, some of which is non-recurrent (or Ôincident-basedÕ) congestion. Commuters are then assumed to make their decisions on the basis of a minimum perceived travel disutility, which can be influenced through the provision of advice from an ATIS. Similarly Yang and Huang also consider the impacts of ATIS, but their focus is on the evolution of market penetration of ATIS. Previous research in the field had indicated that the benefits of the use of ATIS increase initially with market penetration, as the numbers of users grow from small initial beginnings, but then may decline at penetration levels above some optimal amount and may even yield negative benefit (increased total travel time) in some situations, due to over-reactions by ATIS users. This has led to a general transport policy conclusion that it is only necessary or desirable to equip a limited proportion of vehicles with ATIS. This paper takes a different view, attempting to find an optimal strategy for the market penetration of ATIS that will preserve the benefits of the technology through differential pricing for new ATIS users on the basis of current levels of penetration. In this way net information benefit and heterogeneity in driver behaviour are incorporated as important factors affecting the growth of ATIS usage. The authors discuss the identification of optimal levels of ATIS market penetration in different networks and the service charges that may be levied to achieve the optimum levels. RidwanÕs paper is also concerned with driver route choice decisions. He introduces a fuzzy preference based model of route choice, which can account for drivers who do not necessarily attempt to minimise travel time or cost in their route choice decisions. The fuzzy preference modelling approach considers uncertainty of decision making by individual travellers in a dynamic traffic system, and can be used to support ATIS project implementations. ATIS designed specifically for urban freight operations form a basis for the research described by Taniguchi and Shimamoto. Their paper presents a dynamic vehicle routing and scheduling model that can incorporate real time traffic information using variable travel times in a road network, using dynamic traffic simulation to update travel times. An application of their model to a test network of some complexity indicates that the total costs of freight operations and (in many cases) the total hours of travel of freight vehicles in the network could be substantially decreased through the availability of dynamic travel time advice. This suggests that dynamic scheduling and routing can provide benefits to freight operators, through reducing their costs of operation, and the community, through amelioration of traffic congestion in an urban area. Lo, Yip and Wan move the emphasis of emerging technologies from road-based transport to multi-modal urban public transport systems. Their particular interest is in the study of multi-modal trips, where a traveller uses more that one public mode and/or service to complete a given journey. In an environment with competing private sector operators of transit services and different fare structures and systems, modelling multi-modal trips is complex. The paper presents a nested logit modelling framework that can be used to examine the effects of fare competition on traveller behaviour, operator profitability and network performance. The authors use a case study of the ground transportation system connecting Hong KongÕs international airport to the downtown areas. Asakura and Hato consider the monitoring of pedestrian movements in urban areas, using a variety of alternative tracking technologies. Their paper demonstrates fundamental concepts
Editorial / Transportation Research Part C 12 (2004) 167–169
169
and methods for the use of mobile communication instruments such as cellular telephones for tracking the movements of individual subjects. In addition, they note the requirement to study travel behaviour, for which location information alone is insufficient. To overcome this problem, the authors developed an algorithm to provide various trip attributes for each point recorded in the location positioning data. The validity of the algorithm and the accuracy of measurement are then assessed for a sample of 100 individuals surveyed using the combined data logging system. The final paper in the special issue, that by Clement, Taylor and Yue, describes and models the performance of a conceptual ITS system for the automatic progression of vehicles through a signalised intersection, under the automatic control of in-vehicle and roadside infrastructure. The basic principle is the notion that the queue of vehicles assembled at a red signal can be moved simultaneously as a single block (platoon) once the signal aspect switches to green. Once clear of the intersection, the vehicles in the platoon are progressively released back to individual driver control. The advantage of this automated platoon advancement strategy may be seen in increased throughput and decreased delays for approach lanes at signalised intersections. This technology could offer the opportunities for substantial increases in the capacities of existing intersections or for the alternative use of existing road space (e.g. for increased pedestrian facilities or exclusive bus lanes and transit priority) at intersections whilst maintaining current capacity levels. The special issue should make an informative and creative contribution to research and debate on new ITS implementations for improved traffic and transport planning and operations.
Reference Taylor, M.A.P. (Ed.), 2002. Transportation and Traffic Theory in the 21st Century. Pergamon, Oxford.
Michael A.P. Taylor Transport Systems Centre University of South Australia Adelaide SA 5000 Australia E-mail address: [email protected]