中文摘要：

地下道路在地面的出入口位置影响着地下和地面车流的衔接．文中分析了出入口间相对位置的组合模式，以交织段换道次数为主要判断依据，建立交织段最小长度模型，通过算例，给出寻找连续换道最大关键次数和关键车流的方法，针对交通流的混合特性，运用Matlab编程给出交织段最小长度的离散阈值，为地下道路地面出入口与交叉口最小间距的确定提供依据。

英文摘要：

The location of passageway of underground roads relates to the linkage between the traffic flows underground and aground. In this paper, first, the combination mode of entrance and exit locations is analyzed, and a minimum-distance model of weaving sections is established, with the lane-changing times as the main judgement criterion. Then, the way to find the maximum key times and the key flow for continuous lane change is illustrated. Finally, according to the characteristics of mixed traffic flow, the discrete threshold value of the minimum distance of weaving sections is obtained via the programming calculation with Matlab. The proposed method supplies refe- rences to the determination of minimum distance between the intersection and the passageway of underground roads.