The Technical and Operational Feasibility of Automatic Number-Plate Recognition as the Primary Means for Road User Charging

Abstract

Following the publication of the Government's White Paper on Integrated Transport in July 1998, and a shift in emphasis by Local Authorities away from road building to demand management techniques, the current trend is to a more balanced approach, whereby the use of road-space may be charged to vehicle drivers, i.e. road users pay to use (at least some) roads, just as public transport passengers pay each time they travel. Key to this is the introduction of some form of road user charging or vehicle access control. In urban areas, this may be achieved using paper licences (as in Singapore, 1975–1998), electronic (microwave) tags and transponders (as in Trondheim and Oslo, Norway and in Singapore since 1998) or by the use of automatic video-based licence-plate recognition (ALPR). The use of video-based registration to check whether a vehicle has purchased (or been granted) some form of licence rights to use a particular road or cordoned area on a particular day seems both logical and attractive. However, this form of urban road use pricing has not been operated in anything other than small-scale pilot schemes, and there are a significant number of technical, organisational and operational issues that need to be researched before such a system could safely be implemented for everyday use. This paper is specifically aimed at addressing such key issues, to determine whether in the short term (next 5 years) ALPR could deliver a practical tool for use by local authorities, whether in isolation or as part of a package of applications, to reduce traffic congestion within urban areas.