Abstract: Regional expressway scale is the foundation of transportation supply capacity. Rational scale certification of expressway is the basic method to balance the supply and demand of regional expressway. From the point of economic development, combined with the technical and economic characteristics of the expressway, this paper discussed the scale features including network effects, marginal effectiveness, and efficiency delay of regional expressway. According to the principle of demand oriented and cost oriented combination, the forecasting model was established using bi-level programming approach, considering maximization of the cost-effectiveness of regional expressway network construction, and equilibration of the transportation supply and demand, several constraints of construction were also taken into account. While, the Particle swarm optimization method was used to solve the problem. At the last section, the paper verified the model using the data of a province in the central region of China, forecasted the rational network scale in 2020, and the results showed the rationality of the model.

Key words: highway transportation, expressway, economic adaptability, network scale, bi-level programming

摘要： 区域高速公路规模是形成交通供给能力的基础，高速公路合理规模的确定是调节区域高速公路交通供需平衡的基本方法. 从与经济发展相适应的角度出发，结合高速公路的技术经济特性，探讨了其网络效应与规模经济效益、边际效益递减和效益的时滞性等特点；按照“量需而行”与“量力而行”相结合的思路，采取双层规划方法，考虑区域高速公路网建设的成本效益最大化、交通供给与需求的基本平衡，以及投资等建设的约束条件，建立了预测模型，并采用粒子群算法进行求解；最后以中部地区某省为例，对其2020年高速公路网的合理规模进行了分析预测，对模型与方法的科学性、合理性进行了验证.

关键词: 公路运输, 高速公路, 经济适应性, 路网规模, 双层规划