Modelling Bus Transit Operation: a Basis for Budgeting and Fare Determination
K Abbas, Egypt National Institute of Transport, EG
The main purpose of this research is to construct and demonstrate the applicability of a model that incorporates and simulates the main interactions within a bus transit system. In doing so, the research reviews the rules, practices, procedures, steps and policies involved in the planning and management of a bus transit company. The developed simulation model is meant to estimate route based bus operation parameters and hence assist in budgeting bus activities. The model consists of several interrelated modules, the bus maintenance, operation, procurement (additions/replacements), fare determination and cost accounting modules which represent the supply aspects of bus industry. In addition, the demand analysis module, representing the demand side of bus industry.
The proposed model acts as a tool for developing alternative planning scenarios. A scenario is composed of the user specification of certain relationships between model variables, selection of policies and specification of values for key input parameters. The data and information requirements of the model can be categorized into two main types. The first is data and information that is exogenously specified and remain constant over the simulation period. The second type is data and information that is exogenously specified and can be endogenously updated over time through the simulation period.
The simulation model contains principal structural relationships that describe several aspects of the bus system. The behavior of a system is generally governed by the combination and the strength of the feedback loops that form the structure of such system. The main components and feedback interactions between the components that are captured within the model are portrayed and discussed. These are mainly based on mathematical formulations, accompanied by deterministic specifications, empirical formulations and stochastic representations of some of the variables/parameters involved in bus operation activities/functions. The model is capable of quantifying the effects that might occur as a result of changes in bus operation related practices, procedures, policies, and exogenous key input parameters. The model can produce a set of indicators that describe the various aspects of performance of a bus transit company
The applicability of the model as a tool that can support the planning and budgeting decisions of bus managers is fully demonstrated and evaluated using a case study. This case study is based on real data and information as related to bus route 50 operated by Cairo Transport Authority (CTA). Such data was extracted from CTA annual statistical reports as well as from CTA budget plan. Unavailable required data was logically synthesized in an effort to fully demonstrate the applicability of the model. The required data is classified into geographical zoning and network structure data, fleet database, consumption and cost data, database for potential new buses, service description, and demand pattern. The life cycle depreciation function for buses is also specified. In addition specific fare and fleet replacement/additions policies are selected.
The model simulates the maintenance, operation, and procurement requirements and costs. This will take into account the expected changes in demand patterns and hence in service characteristics. Fares and subsidies are then determined in accordance with the specified fare policies and computed costs. The research concludes with demonstrating the usage of the model in performing scenario analysis as related to the effect of some selected variables including average operating speed, fare policies on demand patterns and hence on the outcome of the model. Key performance indicators are computed to assist in judging the outcome of the simulation runs.
Association for European Transport