Based on analysing the highway planning characteristics in a county region, this paper proposes an optimum tree principle for optimizing lay-out of road and a fuzzy method for e- valuating quality of the network, through investigatings its road and traffic parameters, es- tablishes an optimization model of class composition, and, through combining qualitaive analysis with quantitative and harmonizing model calculation with expert experience, ex- pounds the treatment to the problems such as forecasting, line...