公路网布局的多目标优化模型

Multi-objective Optimization Model for Highway Network Design

针对现有公路网布局优化模型的目标函数过于偏重机动性的缺点,在公路网布局优化模型中引入了可达性的概念,建立了多目标双层优化模型.上层考虑建设资金的约束,以公路网可达性最大和交通负荷度最小为目标函数;下层与传统的4阶段交通规划模型相结合,采用用户均衡配流模型.为了反映上层模型的两个目标函数之间的trade-off关系,设计了基于Pareto最优的求解算法,并采用进化算法实现.文中提出的方法在北部湾区域公路网布局规划中得以运用.

A multi-objective bi-level programming model for highway network layout optimization is proposed through involving the concept of accessibility, aiming to improve the traditional single-objective, mobility-oriented approach. The upper-level model consists of two objective functions： maximizing the highway network accessibility and minimizing the traffic load, taking account of the restrictions of construction budget. The lower-level model is the user equilibrium （UE） problem in combination with the traditional four-step transportation planning model. In order to reflect the trade-offs between the objectives of upper model, a multi-objective evolutionary algorithm based on Pareto optimal theory is proposed and programmed. The model and algorithm presented in this paper are applied in the Beibu Bay Area highway network planning, and proved to be a useful tool for making the final decision.