Theory And Methodology Of Construction Timing For Rail Transit Projects

A growing numbers of cities in China are planning and preparing to construct rail transit projects which need large scale investment and high operation cost in recent years. Premature construction might lead rail transit projects to low utilization rate which is unreasonable from the economic angle and increase pressures of paying loan and operation subsidy. However, rail transit projects miss the best demand period and cannot meet the demand of city development in the case of constructing too late. Therefore, this dissertation studied theory and methodology of construction timing for rail transit projects, which lays a theoretical foundation for rail transit development planning and decision-making.Firstly, the characteristics of rail transit investment and option to defer investment were analyzed. The geometric brownian motion was used to describe the uncertainty factors of rail transit investment and deduce the influence functions of construction timing. Secondly, the entropy method and system theory were applied to confirm the construction timing type in Beijing. The improved grey uniform analysis (IGUA) was built up to analyze factors affecting transit ridership in Beijing. Thirdly, the construction consequence was evaluated from the aspects of operation and network structure effects, land use situation of transit oriented development (TOD) and ascription equity. Finally, the construction timing theoretic model to ease congestion based on real option was set up. The stochastic variable model based on real option was built up to calculate the optimal construction timing for rail transit projects.The following are the main innovations of this dissertation:1. The geometric brownian motion was used to describe uncertainty factors of rail transit investment including passenger flow and construction cost etc., which reflect the regularity and randomness of uncertainty factors with the time. The influence functions of construction timing of the uncertainty factors were deduced to reveal the influence of deferring investment on the forecast values of operation revenue and construction cost, which provide the basis for analyzing the development law of the uncertainty factors affected by the construction timing.2. The traffic demand was analyzed by the entropy method. The system theory was used to describe evolution of transport infrastructure supply and traffic demand. From the point of coordinated development, the construction timing type including leading, synchronization delay and their mutual transformation forms was evaluated more objectively. Compared with the previous studies, the IGUA considers the differences in change rate and identifies negative correlation between transit ridership and its affecting factors more easily. The difference degree of ranking results was defined in IGUA to determine the length of time series which improves the reliability and stability of analysis results.3. The difference between rail transit investment equity and road investment equity was analyzed. Use equity and ascription equity were defined and given to evaluate equity of rail transit investment. Use equity refers to the benefits of rail transit projects should be shared by the majority. Ascription equity means ticket price should consider the affordability of the middle and low income people in city. The evaluation indices system of construction sequence of rail transit projects were analyzed from the aspects of operation and network structure effects, land use situation of TOD and ascription equity, which embodies different attitudes of operators and passengers towards ticket price of rail transit projects and reflects implementation conditions more comprehensively and objectively.4. The invest opportunity value model of rail transit projects aiming to ease congestion based on population scale was set up. Compared with the previous studies, the model reflects the changes in congestion cost and travel cost after construction. The model analyzes the influence of five uncertainty factors on the invest decision of rail transit projects. They are population growth rate, population scale after construction, social discount rate, time after construction and proportion of travel cost change by rail transit to income.5. The stochastic variable model of construction timing selection of rail transit projects based on real option was built up. The model consists of three maximization goals: operational value, operational value and direct guidable value calculated in the monetary terms, and operational value and guidable value calculated by prospect theory. The influence functions of construction timing, Monte Carlo simulation and OptQuest were used to determine the optimal construction timing which reflects the influence of social benefit on optimal construction timing and provides the basis for selecting the corresponding development strategy of rail transit projects.