Safety Evaluation for Highway Geometric Design Based on Spatial Path Properties

Table 3

Curvature and torsion computation of geometric alignments.

No.	Type	Parametric equation	Curvature	Torsion
1	TT		0	0
2	TP			0
3	ST
4	SP
5	CT
6	CP

Note. denotes changing rate of grade;  = length of vertical curve; i₁, i₂ = grades of the former and latter tangents, respectively; and  = algebraic difference in grades.