秦岭终南山特长公路隧道规模庞大，通风系统复杂，为了合理确定通风配置，节约通风费用，评估自然风和交通活塞风等非机械式通风方式的通风效果就显得非常重要。通过对秦岭终南山特长公路隧道洞内自然风速、交通活塞风速及交通量的现场监测，收集了大量数据。通过对监测数据的处理、分析得出，较大自然风速出现在11：00~13：00这个时间段，最大达到2.576m/s；隧道东、西线交通量出现高峰期的时间段基本不变；西线风速较大的时间段基本上与交通量高峰期时间段相吻合，而东线风速较大的时间段基本上与交通量高峰期时间段有出入，风速变化也相对平缓。

Zhongnanshan extralong highway tunnel crossing Qinling Mountain is a largescale project that has complex ventilation system. In order to properly determine the ventilation scheme and to save the ventilation cost, the estimation of the ventilation effect of nonmechanical ventilation is very important. Based on the analysis of the monitoring data achieved from field monitoring of the natural air speed, traffic piston air speed and traffic volume, the authors conclude that the high natural air speed occurs from 11:00 to 13:00 with the maximal speed reaching 2.576m/s; the rush hour in the east tube and in the west tube has almost no change; the  high air speed in the west tube occurs almost at the same time as the rush hours while the high air speed and rush hour in the east tube does not match and the air speed is nearly stable in the east tube.