Privately financed infrastructure has attracted a lot of interest in the last decade. Tolled motorways, bridges, tunnels, urban ringroads and other infrastructure works are now increasingly familiar everywhere in Europe, and it is likely that much more of this will be coming. The type of traffic forecasting required by privately financed infrastructure is quite different from that used for the more traditional government financed infrastructure. Instead of forecasting some sort of "longer term equilibrium" demand level as an input to a societal cost/benefit or multicriteria analysis, the emphasis is much more on predicting the short term revenues, year by year, in order to determine the key economic indicators to guide the financial decision process. Important issues are: the accuracy of the forecasts: any forecast is likely to be wrong, but the error margin clearly needs to be minimised: how can this be done? the uncertainties involved: what are the chances that the revenue will be substantially different from what was predicted due to uncontrollable external factors? the time profile, or the build-up of demand: how quickly will the potential users of the new facility actually use it? (A)
Abstract