Crowding and public transport: A review of willingness to pay evidence and its relevance in project appraisal

This paper reviews public transport crowding valuation research, using a number of primary studies conducted in the UK, USA, Australia and Israel. We identify three measures used to value crowding (a time multiplier, a monetary value per time unit and a monetary value per trip), and associated ways of representing crowding in stated preference experiments. Although a number of different types of crowding in terms of location are identified, namely in-vehicle, access-way, entrance and platform/station, the majority of reviewed studies investigate only in-vehicle crowding. Despite the different characteristics of the reviewed studies, they all report that crowding would increase the value of travel time savings, which can be viewed as an additional component of generalised time. This paper also comments on the role that the WTP for crowding reduction can play in project appraisal, and suggests some important avenues for future public transport crowding valuation research.