Spatial Influence Analysis of Traffic Safety in Diverging Areas between Freeway Segments and Off Ramps

Table 1

Continuous variables description for diverging area analysis.

Variables	Description	Sum	Mean	Std. deviation	Maximum	Minimum
Ramp.Length	The length of a ramp in mile	11.67	0.16	0.10	0.54	0.03
Ramp_ADT	Average daily traffic of a ramp	361.82	5.03	4.18	14.73	0.02
Up_Interstate.Length	The length of up interstate in mile	33.10	0.46	0.54	2.78	0.01
Up_Interstate_ADT	Average daily traffic of up interstate	2689.53	37.35	14.92	64.08	11.78
Down_Interstate.Length	The length of down interstate in mile	19.73	0.27	0.17	0.79	0.03
Down_ADT	Average daily traffic of down interstate	2327.76	32.33	13.24	58.48	10.66
IRI	Pavement roughness in inches per mile	101.29	1.41	0.40	2.43	0.00
Median_Width	Median width in feet	524.30	7.28	7.15	18.30	0.00
Speed_Limit	Speed limit	4327.85	60.11	12.42	74.56	31.07

Notes: the number representing average daily traffic (ADT) is in thousand.