The Use of Contingent Ranking for Variations in Air Quality Validation Due to Ixansportation Projects
Changes in air quality are one of the usual consequences of investing in new roads. If the new investment generates many new trips or modal change from the public transport to the private vehicle, the overall effect is likely to be negative. On the other
As this paper shows, a recent cost-benefit study of a major tolled urban motorway - called "Tunels de Vallvidrera"- in Barcelona has involved an ad hoc valuation of the improvement in air quality. Estlm~ting the money value of air pollution abatement is p
As this paper shows, a recent cost-benefit study of a major tolled urban motorway - called "Tunels de Vallvidrera"- in Barcelona has involved an ad hoc valuation of the improvement in air quality. Estlm~ting the money value of air pollution abatement is probably the most complex part of the cost-benefit study. There are several methods to e~mAte such a value, the most standards being hedonic prices and contingent valuation. The method used to elicit it has neither been the standard contingent valuation, nor all indirect technique, but the more advanced contingent ranking method, which is far more reasonable for respondents and minimlses the risk of strategic behaviour, which is the most serious potential bias. This method is starting to gain supporters in the environmental economics field and has a great deal of poss£ble uses for transportation, as this first application shows. The first part of the paper is devoted to the description of the three methods mentioned, and the theoretical foundations of direct techniques. The second part explains how the social value was calculated for Barcelona and how it enters a standard cost-benefit analysis.
SHARP D, University of Kent and TIGHT M, University of Leeds, UK
Association for European Transport