Automatic Vehicle Location: Implementation, Application, and Benefits in the United Kingdom

Automatic vehicle location (AVL) is playing an increasingly important role in public transport operations in the United Kingdom, providing support for real-time management and control of bus fleets and the platform for other beneficial functions including passenger information systems and bus priority. The current and emerging use of AVL in the United Kingdom for public transport is considered in this paper, focusing in particular on developments in London and Southampton where substantial use is being made of AVL. Following a summary description of AVL systems and technologies, examples are presented of the use of AVL for real-time passenger information at bus stops, particularly the COUNTDOWN and STOPWATCH systems in London and Southampton, respectively. Technical aspects are described together with evaluation results including passenger attitudes and financial criteria. Positive results in both cities have led to commitments for citywide implementations. The use of AVL in applications for bus priority at traffic signals is described, including a comparative review of different architectures and techniques that have emerged. Results of a feasibility study for the use of AVL in this context in London are presented. This study indicated that using AVL to target high-occupancy, high-headway buses with higher levels of priority could provide economic benefits for buses and passengers up to twice those achieved with current operations, where priority is equally available to all buses. Deployment details of this application, related to COUNTDOWN, are described. The paper concludes with the outlook for AVL, particularly for greater integration with traffic control systems, where significant potential benefits are outlined.