Public transport demand in Freiburg: why did patronage double in a decade?

The German city of Freiburg has experienced an enormous and unprecedented rise in the demand for local public transport since the early 1980s. This study investigates the causes of this dramatic increase in the popularity of both tram and bus use. Although traffic restraint measures and improvements in the quality of the public transit service are significant factors, the main explanation lies in the introduction of low cost `environmental' travel cards with the key characteristics of transferability across friends and family and wide regional validity across operators. These season tickets considerably augmented transit demand without seriously exacerbating the operating deficit.