Metros reduce car use in European cities but trams do not

Abstract: Despite the evident drawbacks, car ownership and usage continue to rise globally, leading to increased pollution and urban sprawl. As alternatives, Active Mobility and Public Transport are promoted for their health, economic, and environmental benefits. However, the efficiency of Public Transport varies widely. Metro systems, in particular, offer a high-capacity, long-distance solution, but they are expensive and only found in a limited number of cities. Trams, on the other hand, may serve as a substitute. This study compares the modal share in European cities, analysing the differences between those that have a metro, a tram, or neither. The analysis draws on a comprehensive dataset from CitiesMoving.com, which compiles and harmonises mobility surveys from around the world according to the ABC framework (A for Active mobility, B for Bus and other forms of Public Transport, and C for Cars). Findings reveal that cities with a metro have a significantly lower share of car journeys than those with only a tram or no rail system.