Flat fare over urban network

In this structure the same fare is paid irrespective of the length of the trip, but is normally only valid for a single boarding rather than a journey involving an interchange. It may also be applied within a single mode, for example where buses function primarily as a feeder to mass-transit modes such as bus rapid transit, light rail or metro. In rare cases, the flat fare covers linked trips within a single journey across the urban area (sometimes with a time limitation), thus requiring a continuing travel authority within the original ticket.

Its application is more common in urban areas where fare-box revenues only cover a relatively low proportion of system costs, and in moderately sized cities. Setting a flat fare for full cost recovery would strongly discourage short-distance ridership; clearly this impact increases the greater the possible length of trips that can be made.
Further, this fare structure results in passengers making long journeys being cross-subsidized by those making shorter trips. In some cases that might support a societal objective where the poor live at the outskirts of the urban area. However it might have contrary consequences should the urban sprawl include low-density suburbs for the more affluent, and if high-density suburbs have developed close to economic opportunities so as to provide a walking option for travel by the poor.

Where there is also a fares cap, the only rational commercial response of an operator to this fare structure is then to reduce the length of the stage for which the fare applies and artificially break down the journey into segments. The negative impacts of this historic practice can still be observed in most African cities, with forced transfers often being required at the interchanges originally developed for the purpose.