A Novel Approach for Operating Speed Continuous Predication Based on Alignment Space Comprehensive Index

Table 1

Site geometric design characteristics.

Variable	Minimum	Maximum	Mean	Standard deviation
Design speed (km/h)	60.00	120.00	108.32	15.62
Horizontal curve radius (m)	400.00	3500.00	868.05	218.65
Curve length (m)	284.22	1155.48	902.65	89.37
Deflection angle of horizontal curve	6.51	71.12	37.22	12.36
Length of spiral curve	135.00	1800.00	728.93	106.32
Tangent length (m)	121.00	2245.00	1253.28	185.21
Grade (%)	−5.40	5.00	0.63	2.57
Length of vertical grade (m)	160.00	1300.00	776.89	165.79
Lane number	4.00	8.00	6.75	0.93
Lane width (m)	3.50	3.75	3.70	0.12
Left shoulder width [hard/soft] (m)	[1.00/0.75]	[1.25/0.75]	[1.17/0.75]	[1.02/0]
Right shoulder width [hard/soft] (m)	[3.00/0.75]	[3.50/0.75]	[3.35/0.75]	[0.56/0]