Research on the Planning Model and Its Genetic Algorithm of the Road Network Programming

After analyzing and summarizing the characters of the objectives and constraints of the existing road network planning model, the author established a bi-level and multi-objectives planning model aiming to meet the requirement of the planning of the road network: in which the upper-level planning model places the system optimization as the core and realizes many objectives, such as the least travel cost, the largest capacity and the highest technical grade on the basis of the basic need of the road network and the investment; the lower-level planning model is the stochastic users´ equilibrium (SUE) model, in which users choose the roads with the least travel cost or the ones that are regarded so. According to the characteristics of the model, the genetic algorithm as the solution strategy is put forward. At last, the author validates the model and its algorithm with an example.