Abstract: Abstract: This paper sets up the production model of the trucks.The development process of the relationship between the transport capacity increase and the productivity of the freight transport and the causes of this process are analyzed with examples. And this paper then proves that the relationship between the input and the productivity of the trucks accords with the regular patterns of the economics and the improvement of the freight transport capacity experiences the two periods of the fringe productivity increasing and descending. The effects of the market modification and the demand increase dominate the transport capacity supply in our country and the transport capacity is in configurable redundancy. Based on the analysis of the major factors influencing the transport capacity increase and the truck productivity, the paper advances the ideas about improving transport capacity. The ideas lie in the technology improvement of the transport organization, management，and scale produce.

Key words: freight transport, produce model, transport efficiency, example analysis

摘要： 建立了公路载货汽车生产模型，实证分析了我国公路货运行业运力增长与生产率之间关系的演变过程及原因，证明货车投入与货车生产率关系符合经济学规律;认为以往我国实现公路运力增长经历了边际生产率递增和边际生产率递减两个阶段;目前我国运力供应主要受市场调节作用和需求增长的影响，存在运力结构性过剩.在分析影响运力增加和货车生产率主要因素基础上，提出今后运力增长应主要通过运输组织与管理的技术进步、采用规模生产经营方式来实现.

关键词: 公路运输, 生产模型, 运输生产率, 实证分析