近年来在高速公路或快速道路上因车辆发生换道导致的交通事故频发，且后果都很严重． 为此提出了面向高速公路的安全换道预警模型． 首先描述了车辆换道过程和发生换道的动机;然后设计了模拟换道过程的场景，分析了车辆可能发生的碰撞类型;进而以避免发生碰撞为前提，分析车辆在换道过程中与周围相邻车辆间的位置关系，寻找出车辆发生碰撞的临界位置，并以此为依据，研究得到避免车辆发生碰撞的安全距离条件;最后以匀速换道为实例，验证了模型的有效性．

In recent years,traffic accidents caused by vehicle lane changing on highways or fast roads have becomefrequent and have caused serous consequences.Aiming at this problem,a lane changing pre-warning model for high-ways is proposed in this paper.First,the process and motivation of lane changing are described.Next,the simulationscenario of lane changing is designed,and the possible vehicle collision types are analyzed.Then,the position rela-tionship between the lane-changing vehicle and the adjacent vehicles are discussed on the premise of avoiding anycollision,so as to find out the critical position of a vehicle collision.On this basis,a safe distance which can be usedto avoid vehicle collisions is presented.Finally,the proposed model is proved to be correct by an example of lanechanging in uniform motion.