Probability of Roadside Accidents for Curved Sections on Highways

Table 3

Decision rules.

No.	Classification level				Percentage (%)
	1	2	3	4
1	≤40	—	—	—	0
2	40 < V ≤ 60	R ≤ 200	μ ≤ 0.2	—	52.9
			0.2 < μ ≤ 0.8		0.8
3		200 < R	—	—	0
4		R ≤ 300	—	—	60.5
		300 <R ≤ 400	—	—	5.1
		400 < R	—	—	0
5	60 < V ≤ 80	R ≤ 300	μ ≤ 0.2	—	100
			0.6 ≤ μ ≤ 0.8	—	30.3
6			0.6 ≤ μ ≤ 0.8	Truck	59.4
				Car	9.1
7		300 < R ≤ 400	≤ 0.75	—	4.2
			≥ 1.5		0
8	80 < V ≤ 100	300 < R ≤ 400	≤ 0.75	—	66.7
			≥ 1.5		10.7
9		400 < R ≤ 600	≤ 0.75	Truck	34.2
				Car	0
			≥ 1.5	—	0.4
10	100 < V ≤ 120	300 < R ≤ 400	Truck	≤ 1.5	76.7
				≥ 2.25	32.5
11		400 < R ≤ 600	Truck	≤ 1.5	67.6
				≥ 2.25	0
12		200 < R ≤ 300	Truck	α < 4	80.6
				α ≥ 4	100

Note: V represents the vehicle speed (km/h), R is the horizontal curve radius (m), μ represents the adhesion coefficient, denotes the hard shoulder width (m), α represents the longitudinal slope (%), and — indicates that the risk factors at the corresponding decision rules have no significant impact on roadside accidents.