Analysis to the key of setting out and calculation oval curve based on baseline of tangency

The paper deals with the measuring and calculation of the complicated oval curve of high class-highway,which is interpreted by full horizontal curve including the oval curve is divided up two typical alignment consisting of the dissymmetrical curve and special dissymmetrical curve,and the computational method and process of the radius of the second circle curve in detail based on the theory of tangent baseline and the selected design parameters,which is introduced by the key application point and the example.