Driving Risk Affected Areas and Distribution Function of Sharp Horizontal Curves of Expressway

Table 3

Normalization processing results of crashes of SHCs.

Category	Mean (%)	Standard deviation	Minimum value (%)	Maximum value (%)
Total	16	10.46	0	44.44
Subsection 1 (affected area before entering SHC)	12.23	3.83	8.33	25.32
Subsection 2 (1st spiral curve)	34.89	5.67	16.67	44.44
Subsection 3 (1st 1/2 circular curve)	21.38	4.24	12.5	33.33
Subsection 4 (2nd 1/2 circular curve)	15.47	4.48	8.33	30
Subsection 5 (2nd spiral curve)	10.70	2.42	5.88	16.67
Subsection 6 (affected area after exiting SHC)	5.72	5.1	0	18.18