Evaluating the Effect of Roadway and Development Factors on the Rural Road Safety Risk Index

Table 1

Definition of variables included in the link-based dataset and descriptive statistics analysis.

Variable		Link-based dataset	No. of samples	Minimum	Maximum	Mean	Std. deviation
	Accident frequency rate	No. of accidents/segment length	106	0.00	12.66	0.40	1.44
Roadway and development factors	Operating speed	—	106	50.10	106.00	83.87	12.39
	Difference between posted speed and operating speed	—	106	-29.40	59.20	23.48	16.81
	Segment length	—	106	0.10	5.20	1.62	0.88
	Volume	(AADT)1000	106	10.84	22.27	17.58	4.52
	Presence or absence of a speed control camera	Binary variables: “1,” presence; “0,” absence	106	0.00	1.00	0.03	0.17
	Homogeneous sections	Binary variables: “1,” straight section; “2,” straight uphill section; “3,” uphill section; “4,” straight downhill section; “5,” downhill section; “6,” horizontal curve section	106	1.00	6.00	4.08	1.97
	Gradient	G1: links with a median gradient below; −0.3% (downhill); G2: links with median gradient between ±0.3% (Even); G3: links with a median gradient above +0.3% (uphill)	106	0.00	2.00	1.17	0.93
	Dominant land uses along the roadways	Binary variables: “0,” residential; “1,” commercial; “2,” for other land uses	106	0.00	2.00	0.94	0.92
	Number of accessibility	—	106	0.00	10.00	2.31	2.38

Note. AADT: annual average daily traffic.