Valuing transport investments based on travel time savings—a response to David Metz

David Metz's recent case study published in this journal argues that the conventional approach to the economic appraisal of transport projects is inadequately evidenced and likely to lead to inconsistency with policy goals. In his view, these shortcomings have been further demonstrated by the recent UK study of the value of travel time savings (VTTS), and radical reform of appraisal is required. Metz makes some good points, but many of his key arguments are unsound. This paper responds to Metz's arguments, including his critique of the VTTS concept and the recent UK study on this subject. The paper argues that the preferred approach to appraisal should be an evolutionary one, bringing together the transport sector impacts and the planning and economic development impacts in the overall transport business case.