Through the analysis about superelevation calculation in middle of S type curve,The author brings forward the improvement method of oblique ridge road arch in convolution engagement of S type curve.

• 根据S型曲线在超高过渡计算时遇到的具体情况进行分析,提出了对"S型曲线"在两反向回旋线衔接处进行用斜脊式路拱设计的改进方法。