Exploring Driver Injury Severity in Single-Vehicle Crashes under Foggy Weather and Clear Weather

Table 3

Model estimation results of SVCC.

Variable	Description	Slight injury			SFI
		Mean	S.E.	z-value	Mean	S.E.	z-value
Driver characteristics
Gender	Male	−0.702	0.162	−4.33	−0.491	0.267	−1.84
	Std. dev.	–	–	–	1.241	0.108	–
Age	>60	1.192	0.194	6.14	2.151	0.244	36.13
Seat belt used	Not used	0.370	0.132	2.80	2.004	0.170	11.79
Alcohol-impaired	Yes	0.950	0.183	5.19	3.580	0.194	18.45
Career	Self-employed	–	–	–	−0.624	0.265	−2.35
	Farmer	–	–	–	−0.450	0.207	−2.17
Driving license	With license	−0.681	0.161	−4.23	−0.826	0.227	−3.64
Vehicle characteristics
Vehicle type	Motorcycle	2.594	0.143	18.14	2.442	0.226	10.81
	Pickup	−0.638	0.167	−3.82	−0.692	0.318	−2.18
	Truck	–	–	–	−0.776	0.253	−3.07
Other characteristics
Area	Rural	0.278	0.109	2.55	0.403	0.166	2.43
	Std. dev.	1.015	0.074	–	–	–	–
Week	Weekend	–	–	–	0.540	0.176	3.07
Time of accident	07 : 00–09 : 00	−0.268	0.127	−2.111	–	–	–
	20 : 00–24 : 00	1.056	0.209	5.05	1.412	0.299	4.72
	00 : 00–07 : 00	–	–	–	0.981	0.254	3.86
Crash type	Fixed object	1.791	0.253	7.08	3.440	0.285	12.07
	Pedestrian	−1.997	0.216	−9.25	−2.800	0.454	−6.17
Intercept		−1.994	0.228	−8.75	−4.917	0.401	−12.26
Likelihood ratio	χ^2(56) = 3350.98;
McFadden pseudo R^2	0.434
Sample size	4999

Note: and indicate that variables are significant at 1% and 5% significance levels, respectively; S.E. means the standard error; – means this variable is not significant in the model.