An Improved Deep Learning Model for Traffic Crash Prediction

Table 2

Summary statistics of analyzed categorical variables.

Variable	Category	Frequency	Percent
Geometric design features
Number of through lanes	3	585	18.43
	2	1660	52.28
	1	930	29.29
Lane widths (ft)	12	915	28.82
	11	1650	51.97
	10	610	19.21
Number of left-turn lanes	2	920	28.98
	1	650	20.47
	0	1605	50.55
Median type	1 for non-traversable median	1185	37.32
	0 for traversable median	1990	62.68
Shoulder type	2 for pavement	760	23.94
	1 for gravel	1595	50.24
	0 for dirt	820	25.83
Environmental factors
Terrain type	1 for mountainous	1206	37.97
	0 for rolling	1969	62.03
Land use type	2 for residential	1622	51.10
	1 for commercial	775	24.41
	0 for rural	778	24.49
Indicator for lighting	1 for lighting exists on the roadway segments	1304	41.06
	0 for others	1871	58.94