高速公路中央分隔带开口长度研究

高速公路中央分隔带开口长度影响车辆在开口处的行车安全和通行效率。本文基于5次多项式换道模型对车辆通过中央分隔带开口的行驶轨迹进行研究,通过确定边界条件得到车辆通过中央分隔带的轨迹函数,得到不同限速值和中间带宽度值下的开口长度建议值。根据车辆动力学推导出车辆以限速值通过中央分隔带开口所需最小转弯半径；根据车辆轨迹函数,推导车辆换道轨迹的最小曲率半径；最后将最小转弯半径与最小曲率半径作对比,证明本文给定的中央分隔带开口段长度建议值能够保证车辆行驶稳定性,确保车辆通过高速公路中央分隔带开口时的行车安全。

Research on Opening Length of Medial Strip Diverging of Expressway

Opening length of medial strip of expressway will influence the safety and traffic efficiency of vehicle. This paper studied the traveling track of vehicle when passing the opening of medial strip based on lane-changing model of polynomial with 5 degree. Through determining the boundary conditions, this paper obtained the trajectory function of vehicle at the opening of medial strip and provided advised values of opening length of medial strip under different speed limit values and medial strip width. According to vehicle dynamics and trajectory function, the minimal turning radius of vehicle and the minimal curvature radius of trajectory function were worked out. After comparing the two indexes, the advised opening length of medial strip of this paper was proved to be able to keep the stability and safety of vehicle when moving through the opening of medial strip of expressway.