In the clause the likelihood allocated performance evaluation of investments into transport building taking into account quantitative characteristics of uncertainty and risk is considered by a method of simulation modeling of Monte-Carlo. The process approach and a discrete dynamic model of monetary flows is put in an estimation basis from investment, operational and financial activity in the conditions of external economic benefits and state-private partnership. The numerical example of a likelihood estimation of cost efficiency of investments into building the railway in comparison to the data of the determined estimation, and also results of application of different schemes of financing of the project is resulted.