1,720,980 research outputs found
The way ahead for London’s bus priority at traffic signals
Full text linkLondon has a long history of successful schemes for bus priority at traffic signals. Recently, Transport for London (TfL) has procured a modern automatic vehicle location (AVL) system for bus fleet management, passenger information and bus priority. The new system is known as iBUS and is based on global positioning system (GPS) and supporting technologies for bus location. The system eliminates the need for on-street hardware for detecting buses and provides more flexibility and opportunity for using bus detectors. However, bus location based on this system is less accurate than location based on fixed infrastructure (e.g. beacons) and could result in reduced benefits from bus priority. This paper first summarises how bus priority at traffic signals works within iBUS, and then explores the effects of GPS locational errors on bus priority benefits. This is followed by a discussion of opportunities available in the context of iBUS to build an even more efficient and beneficial bus priority system by taking advantage of its cost-effective multiple detection capabilities. The paper is based on various studies carried out by the Transportation Research Group (TRG) at the University of Southampton for TfL
Review of urban traffic management and the impacts of new vehicle technologies
Full text linkTraffic congestion is a growing problem in most urban areas across the world. In recent years, the problem has often been tackled by management of existing capacity rather than the traditional concept of more road building. This requires efficient traffic management tools and has led to widespread implementation of advanced traffic control systems integrated within a wider urban traffic management (UTM) environment. UTM systems collect data from various sources, process and manage the data and use this information to implement various measures to manage traffic. While infrastructure-based UTM systems continue to develop, there is now also a rapid market-driven development of vehicle technologies and in-vehicle driver support systems. Driver information and satellite navigation (sat-nav) systems are two examples already in widespread use, whereas other applications under research and development include intelligent speed adaptation (ISA), adaptive cruise control (ACC) and various other safety-related applications. This study will firstly present state-of-the-art reviews of UTM and in-vehicle systems. It will then discuss the potential impacts of new in-vehicle systems on UTM and opportunities for beneficial cooperation between the two. The research described in the study has been undertaken within a collaborative project FUTURES, funded by the Engineering and Physical Sciences Research Council (EPSRC
AVL based bus priority at traffic signals: a review of architectures and case study
No full textRecent developments in technologies such as Automatic Vehicle Location (AVL) and advanced control systems have stimulated new interest in bus priority facilities using traffic signals. The use of AVL systems has generated opportunities for implementing flexible bus-specific priority strategies according to performance. The extent of the opportunities available depends very much on the architecture of a bus priority system, including the location(s) of intelligence determining the priority level and its implementation, and the method of priority request to the traffic signal. These aspects are important from the point of view of bus priority performance, communication requirements and the cost of the system.This paper draws together and compares the various architectures currently being used for AVL-based bus priority, providing an overall review to supplement other papers which are usually concerned with individual systems. The paper reviews current bus priority systems used across Europe under five different architecture categories. The present bus priority architecture in London is then analysed in more detail as a case study. The paper concludes with a discussion of issues for this application, given the continuing advances in locations and communication technologies, and issues for the future
A new strategy for differential bus priority at traffic signals for high frequency services
No full textThe need for sustainable transport operations in cities is focusing more attention on the needs of buses to provide fast, frequent and reliable services. One favoured measure is bus priority at traffic signals, particularly where roadspace is limited. With increasing use of AutomaticVehicle Location (AVL) systems, it is now possible to provide ‘differential’ priority, where different levels of priority can be awarded to buses at traffic signals according to chosen criteria. At present, common strategies are based on the comparison of the time headway of abus with the scheduled headway. However, this paper shows that greater regularity benefits could be achieved through a strategy where priority for a bus is based not only on its own headway, but also the headway of the bus behind. This paper discusses this new strategy,demonstrates its benefits on a theoretical basis and provides initial simulation results
Using global positioning system for bus priority in London: traffic signals close to bus stops
No full textLondon's bus network is one of the largest and most comprehensive urban transport systems in the world. The contribution of buses is recognised by implementing a series of initiatives including bus priority at traffic signals. London has a long history of the implementation of bus priority at traffic signals. It has kept pace with the development of new technologies by updating its bus priority system. Now, London is moving towards a bus management system based on global positioning system (GPS), which will also be used to provide bus priority at traffic signals. The authors describe theoretical work carried out by TRG on behalf of Transport for London Bus Priority Team to tackle the challenge posed by locational error associated with GPS where a traffic signal is close to a bus stop
Bus priority at traffic signals: investigating the options
No full textBus priority remains one of the principal strategies adopted in many towns and cities to improve levels of service for bus passengers and to encourage modal change. Interest in recent years has centred on priority facilities using traffic signals, taking advantage of new technologies such as automatic vehicle location (AVL) and advanced control systems. There are a range of system architectures available for using AVL in bus priority. The paper describes the opportunities and options available for the UK and also summarises some bus priority architectures used in Europe. Other issues discussed include: the influence of bus detection strategy on bus benefits where there are bus stops close to the traffic signals, options for high priority strategies and issues related to bus priority at signalised pedestrian crossings. The paper concludes with a discussion of issues of implementation and integration with alternative or complementary measures to help buses, such as demand management. The paper is based on research undertaken within the EC-funded project PRISCILLA, and within continuing studies of bus priority at traffic signals for Transport for London (TfL
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