In April 1989, Wiltshire County Council appointed Transportation Planning Associates to undertake a study of lorries in the County. The objectives of the study were to propose a network for lorry movement and develop a strategy for managing the movement and parking of lorries. Specific studies were required of two areas of intense lorry activity, the fast growing town of Swindon and the area of gravel extraction in the north of the county known as the Cotswold water park. Recommendations on the inclusion of improvement schemes in the county highways programme were required. In order to provide a comparative method of assessment between the environmental improvements and economics of schemes of different types, and to give an indication of environmental performance of various options, an index was devised to assess the exposure of communities to lorry nuisance. The index comprises the product of the length of built up frontage and the logarithm of the number of lorries. The improvements in the index provided by various lorry management and highway construction schemes were compared with the net present cost of the schemes, taking into account construction, enforcement and vehicle operating costs, to provide a cost/ benefit ranking. As the index was designed for a strategic context and is therefore simplified, detailed assessment of options was undertaken in an assessment framework, where the change in the index could be considered in conjunction with other effects of the proposals not incorporated in the index. The paper shows the application of this ranking system to a variety of lorry problems in the county and considers its value as a decision making tool.
Samenvatting