Prof. Alejandro Tirachini present together with Kenneth Løvold Rødseth and Paal Wangsness (Transportøkonomisk institutt (Norwegian Centre for Transport Research), Stef Proost (KU Leuven Institute for Mobility) the first article that accounts for the external health benefits of active mobility in the design of a public transport system (optimal stop spacing and service frequency) and in the optimal pricing of buses, cars, cycling and walking. In doing so, they find that subsidies for walking and cycling are part of the first-best policy for urban transport.
For details, see their open-access paper in the Journal of Urban Mobility.