Abstract
In this paper, the relationship between service quality and the demand for inter-urban rail travel in Great Britain is examined. It tests the elasticities to time, frequency and interchange implied by an approach which combines these three variables into a single term and compares this approach with models which estimate separate elasticities to time, frequency and interchange. It is concluded that more attention needs to be paid to the functional form of direct demand models, particularly those which specify composite variables such as generalised cost, since the forecasts obtained from different model forms can be appreciably different. (Author/publisher).