Abstract
Public transport needs to be fast, frequent and accessible. Non- captives want speed, which requires free lanes and short distances between stops and leads to a few main axles on which traffic- flows are brought together. Captives want accessibility, which requires a great number of dispersed stops. Joining these contradictive demands leads to the need for different sub- systems. In the total public transport system every sub- system plays its own role as well as a feeder- role for a sub- system on a higher level. This makes transfers between sub- systems unavoidable.