[Parution] Alina Bekka, Nicolas Louvet et François Adoue, « Impact of a ridesourcing service on car ownership and resulting effects on vehicle kilometers travelled in the Paris Region », Case Studies on Transport Policies

The question of the impacts of ridesourcing on traffic externalities has emerged as a widely debated topic, and as a fundamental matter to address everywhere ridesourcing services developed. In order to understand these traffic-related outcomes, it is necessary to analyze the effects of ridesourcing on mobility practices. An emerging literature tackles the effects of modal shift linked to ridesourcing use on traffic volume (Vehicle Kilometers Travelled (VKT)). However, the role of ridesourcing in longer-run behavioral change, such as decisions relating to car ownership, has seldom been studied. The present article specifically focuses on Uber’s role in household car ownership reduction and resulting effects on traffic volume in the Paris Region, where ridesourcing has rarely been investigated. We put forward a novel methodology, using a survey of 1966 Uber users, to single out and measure the impacts of ridesourcing on car ownership. Through a Likert scale analysis, we show that Uber does not have an isolated effect on the decision to shed or sell a car without replacing it. The availability of Uber does, however, play a decisive role, along with other factors, in household car ownership reduction for a significant share of users. The use of prediction models eventually leads to a quantified estimation of the VKT that were saved by those cases of car ownership reduction linked to ridesourcing. The net difference between these avoided VKT and VKT Uber drivers generate while connected to the app reveals that the impact of the ridesourcing service on overall VKT in the Paris Region has been minimal thus far. But, as ridesourcing services continue to develop, their prospective ability to contribute to car ownership reduction and traffic-related effects remain unclear. The study’s overall findings bear instructive and potentially far-reaching policy implications, that may guide public authorities in their efforts to regulate ridesourcing services.