为了保证高速行车的安全与舒适,公路线形已越来越多地采用曲线以代替长直线,并以圆曲线、缓和曲线及其组合作为它的主要形式。目前的趋向是采用以曲线为主的线形设计,例如日本东名高速公路直线段仅占全长的4.4％。曲线设计合理,不仅能适应地形地物条件,与周围景观协调舒顺,而且可给司机以适当刺激节奏的安全舒适感。因而,对于圆曲线半径、缓和曲线几何参数以及它们的最小长度计算,必须掌握其计算原理,特别是它的影 In order to ensure the safety and comfort of high-speed driving, highway alignment has increasingly adopted curves instead of long straight lines, and its main forms are circular curves, relaxation curves and combinations thereof. The current trend is to use a linear curve-based design, such as Japan’s Tomei Expressway straight section accounted for only 4.4% of the total length. Curve design is reasonable, not only to adapt to terrain and terrain conditions, and the surrounding landscape coordination and comfort, but also to the driver to stimulate the rhythm of appropriate comfort and comfort. Thus, for the calculation of the radius of the circular curve, the geometric parameters of the easement curve, and their minimum length calculations, the principle of its calculation must be mastered, in particular its shadow