The Development of a Countrywide Speed Monitoring System and Its Contribution to a Comprehensive Speed Management Strategy
D J Ling, C Davies, G Constantinou, University of Manchester, UK; P Andrews, Lancashire County Council, UK
This describes the design and implementation of systematic Countywide speed monitoring on classified non-motorway roads in Lancashire, with representative speed data analysed within a GIS linked to speed limits, road accidents and speed enforcement.
The effective development of a Comprehensive Speed Management Strategy, embracing such issues as road safety, speed limits and their enforcement, and the environmental and economic impacts of traffic, requires a systematic basis for the monitoring of road traffic speeds. This is required to prioritise and guide the implementation of speed management related road safety or enforcement initiatives; to help separate the impact of specific initiatives from that of wider policies or trends, so as to assess their effectiveness; and to establish the extent to which specific localised initiatives have only a local or a more widespread impact on driver behaviour.
Traditionally, however, road traffic speeds have usually been monitored at a limited number of locations, often selected on an ad-hoc basis or in association with specific road safety or speed enforcement initiatives, and such speed measurements have usually been undertaken in an isolated fashion for limited periods of time. The data thus collected lacks the comprehensiveness needed to provide a systematic indication of traffic speeds across a Countywide area, or indeed for a wider regional or national scale. Furthermore, speed data has usually been collected in an aggregated fashion, with the data structured in such a way that only limited comparisons can be made between speed measurements made at different sites, or sometimes even between data collected at the same site on subsequent occasions.
The proposed paper describes the design and implementation of a Countywide Speed Monitoring System covering the classified non-motorway road network of Lancashire. The paper is based on work undertaken by the authors during the past four years both at UMIST [now an integral part of the University of Manchester] and within Lancashire County Council. The resulting Speed Monitoring System captures data from a total of 120 representatively located speed monitoring sites, at which inductive loop detectors are used to monitor individual vehicle speeds. Data acquisition is on a rotating basis, typically over two week periods once every three months or so, with the resulting speed data being interrogated and analysed within a bespoke Geographical Information System, linked to cartographic based displays of speed limits, road accident data and speed enforcement activity. The GIS is constructed within a PC based ARC/View environment, which is both portable and adaptable, ideal for empirical studies. The speed monitoring sites have been selected to give a representative coverage of geography, road environments, speed limits and traffic levels across the whole County.
The paper will describe the reasons for establishing the Countywide Speed Monitoring System and its intended objectives. It will outline the design of the system, including the establishment of the number and representative distribution of speed monitoring sites, the identification of their preferred location, the choice of discrete individual vehicle speeds as the form of data to be collected, and the specification, selection and installation of the speed monitoring equipment. The paper will then indicate how the resulting speed data is analysed and displayed within the bespoke GIS, utilising enhanced cartographic displays based displays to provide a comprehensive appreciation of the interactions between road safety management and speed enforcement activities and their apparent impacts on traffic speeds and on road accidents.
The paper will conclude by presenting selected results of analyses and example displays from the Speed Monitoring System, and by discussing the contribution of systematic speed monitoring to the development and implementation of a comprehensive Speed Management Strategy. It may also indicate some ideas for possible further developments in the speed monitoring system and the scope that it provides for more detailed research on traffic speeds than has been possible with the typically available traditional sources of traffic speed data.
Note of Background to the Authors and Proposed Paper:
The paper is based on a Consultancy Study undertaken at the University of Manchester Institute of Science and Technology [UMIST] on behalf of Lancashire County Council, and on related work undertaken by Lancashire County Council?s Environment Directorate and their suppliers and contractors. The work at UMIST was supervised by David Ling, in the then Manchester Centre for Civil & Construction Engineering, and by Dr Chris Davies, in the then Department of Computation, and was undertaken by them and their researcher, George Constantinou, with the assistance of Ted Harding, of the then UMIST Statistical Advisory Unit.
Some aspects of the work undertaken at UMIST formed the basis of an MPhil thesis recently submitted by George Constantinou. David Ling is an expert in various aspects of urban transport policy and has previously authored and presented many papers at international conferences, including six full papers and two other presentations given at the PTRC Summer Annual Meeting [the predecessor conference to ETC], and two papers given at the ETC 2004 conference. Chris Davies is an expert in Geographical Information Systems, Systems Engineering and Social Geography, and has authored many papers for both academic journals and international conferences. UMIST became an integral part of the re-constituted University of Manchester from October 2004.
The proposed paper will be jointly authored by David J Ling, Chris Davies and George Constantinou from the University of Manchester, and by Peter Andrews of the Environment Directorate at Lancashire County Council. Peter Andrews acted as the principal contact at Lancashire County Council during the Consultancy Study and lead the subsequent implementation by Lancashire County Council of the resulting Countywide Speed Monitoring System. He is responsible for road safety engineering and has been directly involved in the integration of the speed monitoring system with their other GIS based road safety related information systems and with the development of Lancashire?s Speed Management Strategy.
Please note, Peter Andrews? contribution to the paper will draw also on the experience of other staff at Lancashire County Council who have been involved in the implementation of the Countywide Speed Monitoring System, in particular Martin Galloway and Rob Mather. The list of authors from Lancashire County Council given in the final paper may therefore be extended to include the names of these or other LCC staff.
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