Research On A Linkage Adjustment Model Of Concession Period And Toll Price For Highway Bot Projects

As a newly developed operation mode of project, BOT (build-operate-transfer) has great advantages in financing, management, technical innovation, and has achieved greatly results in the field of infrastructure construction of many countries and regions of the world. Highway BOT projects can reduce the financial burden greatly, improve the efficiency of operation and meet the needs of the public traffic. However, some BOT projects are usually out of control during the operation process because of huge investment, high risk, complex stakeholders and etc. It is hard to achieve risk-sharing and win-win between the government and the project company with a single adjustment of concession period or toll price. Based on this, considering the benefits of the government departments, the project company and the social public, the study and research are given on a linkage adjustment model of concession period and toll price for highway BOT projects.Firstly, the relevant literatures and data of traffic BOT projects at home and abroad are collected and summarized, the impact factors and decision making methods of BOT projects are analyzed, the scope of concession period is defined, the classification and adjustment of the concession period are summarized, and the toll price adjustment methods are classified. This lays a theoretical foundation for the linkage adjustment model for highway BOT projects based on fair return. Furthermore, it presents research background and current situation, principal theorem, systematic structure, causal loop diagram, stock and flow diagram of system dynamics. It also deeply studies the development situation, principal theorem, and fuzzy control system of fuzzy logic. This helps to establish methodological basis for the linkage adjustment model.Secondly, the paper gives the causal loop diagrams on the basis of identifying the influence factors and mutual relations of highway BOT projects. Then, a stock and flow diagram model about income is constructed on the basis of causal loop diagrams. In the same time, using fuzzy logic method, it puts the membership function into the MATLAB toolbox, makes the qualitative data quantification, and completes the mathematic expression of the stock and flow diagram model. Combines with the object set and runs the model, it can obtain several linkage adjustment schemes of concession period and price, according to the fuzzy multi-objective decision method, selects the optimal satisfying scheme of stakeholders. Furthermore, this paper tests and verifies the linkage adjustment model by a simulation example, and then calculates the NPV and concession period from high risk situation, normal condition and low risk situation of BOT projects. Adjustment methods about high risk and low risk conditions are given by concession contract; on the basis we can get an adjustment interval of toll price, which can offer reference to the government and the project company in making linkage adjustment decisions for highway BOT projects.Finally, the research of this paper is systematically reviewed and summarized, the deficiency in the study is given, and moreover the ideas and thoughts for further research are provided.