Safety Evaluation for Highway Geometric Design Based on Spatial Path Properties

Table 2

Combined forms of highway geometric alignments.

No.	Type	Horizontal alignment	Vertical alignment	Parametric equation
1	TT	Tangent	Tangent
2	TP		Parabola
3	ST	Euler spiral	Tangent
4	SP		Parabola
5	CT	Circular curve	Tangent
6	CP		Parabola