Study on bi-level planning model & algorithm optimizing highway network layout

With the rapid development of socioeconomy and communications and transportation, the demand for highway network planning and construction continuously increases. The single objective optimization model was adopted in the past, which can not reflect the objective and overall demand of highway constructions and users. Based on this, the demand of provincial or urban level highway network layout is firstly analyzed in this paper, then through optimizing the continuous variables and introducing the bi-level planning model, this paper establishes bi-level planning model which is fit for provincial or urban level highway network layout optimization. Finally the solution algorithm is studied and the simulated annealing algorithm is applied to highway network layout optimization problem in this paper, applying program language of Visual Basic 6.0, this paper developed corresponding algorithm program. The algorithm is especially apporipriate for solving large scale network optimization problems.