The economic cost of subway congestion: Estimates from Paris

Related to the increased encouragement of public transport (PT) by policy-makers, over-crowding in PT has become a major issue worldwide. Whilst the impact of in-vehicle crowding on individuals' travel costs has been considered, we focus on aggregate welfare losses. We apply a Pigouvian framework to the case of subways and compute the economic cost of congestion (ECC). We combine data of the 14 metro services of the Paris network with survey data from a contingent valuation study of in-vehicle congestion. The gap between current and optimal PT patronage is 9%, and ECC is moderate. For the entire Paris subway network our benchmark estimate of 64.6 million euros per year amounts to 0.9% of total users' costs. We also propose marginal congestion costs relevant for socioeconomic appraisals of transport projects.