Patronage forecasting is a key issue in strategic transport planning, because it is relevant to financial and economic assessment and thus to the choice between alternative public transport (PT) modes. This paper reports on research to develop a comprehensive framework for PT patronage forecasting, then bring it to the modelling stage. The policy considered consists of changes in the supply of transport services and infrastructures, represented by providing a new PT mode on a given route, called the `PT linehaul mode'. The relevant modes, representing the supply side, include: (1) the PT linehaul mode; (2) PT and non-PT access and egress modes, some of whose characteristics are changed; (3) PT and other modes, competing for the PT linehaul mode, some of whose characteristics are changed; and (4) PT and other modes of access/egress and in competition with the PT linehaul mode, whose characteristics are assumed unchanged. The change in level of service, resulting from the policy, affects travel decisions and land use. A patronage forecast over a given period is obtained by combining forecasts from short sub-periods. The following modelling issues are discussed: modelling framework, modelling approaches, basic features of a restricted-area model, modelling the effects of PT supply changes, and implementation.
Abstract