Calculation method of economic evaluation indices for highway engineering project

To effectively evaluate the alternatives of highway engineering project with fuzzy basic data and parameters, an economic evaluation indices system was set up, the indices were proposed as trapezoidal and triangular variables, their fuzzy calculations were completed in the same or different possible spaces, the membership of every index was gained by using Zadeh's expansion principle, the credibility value, key value and expectation value of every index were computed by using fuzzy simulation technique, and the alternatives were evaluated based on the computation values.Evaluation result shows that the fuzzy expectation net present value of the alternative is more than 0, the credibility value is 100%, so the alternative is feasible, and the outcome of the evaluation is objective.