Study On Comprehensive Quantitative Evaluation Of Interchange Schemes

Comprehensive evaluation of interchange schemes is not only a basic work of interchange design, but also an important link between different design phases. Actually, the success of interchange design depends on schemes selection, a bad scheme will lead to a bad interchange. This paper first analyses factors which should be considered during schemes selection, then puts forward a new index system of comprehensive evaluation based on studing the existing evaluation index systems of interchange schemes. The index system basically summarizes the need of traffic safety, transport function, economic efficiency, environmental impact, construction and so on. The methods to calculating the indexes are also presented.Through analysing the characteristics of objective weighting and subjective weighting, this paper makes out a combination weighting based on improved analytic hierarchy process(AHP) and entropy value method. After studing the disadvantage of 1～9 scale in existing AHP, this paper proposes an improved AHP based on the scale of e 0/5~8/5. It utilizes entropy value method as objective weighting, then combines subjective weights and objective weights through linear weighted method.This paper analyses the principles, advantages and disadvantages of two comprehensive evaluation methods commonly used, Fuzzy Comprehensive Evaluation(FCE) and Grey Relational Analysis(GRA). It points out the characteristics of interchange schemes evaluation, quantitative and qualitative combined, fuzziness and grey coexist; then a new comprehensive evaluation method combined FCE and GRA is proposed. At last, an example is given to test the feasibility and applicability of the theory.