A technique for estimating volumes of seasonal recreational traffic on rural roads has been developed by the tourism and recreation research unit of Edinburgh university using data from the TRRL 50-point traffic census. Harmonic analysis was used to develop a model which gives a prediction of total daily flow for each day of the year. The model is calibrated on data consisting of automatic traffic counts for the road in question taken during two fortnight periods, one in winter, one in summer. Methods were developed to predict the likely mean error in using the model to estimate volumes of daily traffic, based on the estimated or observed flow characteristics for the road. From the forecasts of total traffic, the seasonal recreational and holiday traffic component can be estimated by applying the 'surplus traffic' hypothesis. This states that levels of non-summer traffic represent mainly 'utility' traffic which can be expected to maintain a relatively constant level throughout the year. Subtracting an estimate of utility traffic from the total traffic flow yields the seasonal recreational component. Evidence supporting this hypothesis, modified to allow for winter recreational flows, is presented. The final traffic 'mix' model was tested using data from two Scottish border roads. Results were satisfactory, but further testing would be appropriate when suitable data become available. (Author/publisher)
Abstract