The costs of mobility in the Paris region.

Transport accounts have been established in the Paris region since 1981. Their main objectives are: (a) to assess the economic expenditure for urban transport in the Ile-de-France region (considering private cars, public transport, taxis and cycles); (b) to assess the economic and external cost (noise, atmosphere pollution, congestion and traffic accidents of each model); and (c) to assess the funding contribution of the various economic agents, such as users, taxpayers, public institutions, and employers. This paper gives an overview of transport accounts in the Ile-de-France region over the last 15 years and explains the main reasons of the observed evolutions. It also proposes a comparison of trip costs by mode for the collectivity, taking into account all kinds of costs: (1) public costs (fuel, maintenance depreciation for car users or ticket prices for public transport passengers); (2) public costs (investments and operating costs, consumptions of space); and (3) external costs. This analysis emphasizes the role of fuel and public transport pricing on the one hand and of parking availability on the other hand. It shows the distortion between trip costs for the collectivity and the perceived costs.