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

Table 4

Model estimation results of SVCF.

Variable	Description	Slight injury			SFI
		Mean	S.E.	z-value	Mean	S.E.	z-value
Driver characteristics
Gender	Male	−0.948	0.176	−5.39	−1.132	0.255	−4.44
	Std. dev.	–	–	–	0.881	0.120	–
Age	<30	–	–	–	−0.476	0.158	−3.01
	Std. dev.	–	–	–	1.10	0.106	–
	>60	1.100	0.195	5.64	1.834	0.225	8.15
Seat belt used	Not used	0.262	0.109	2.40	1.017	0.134	7.59
Alcohol-impaired	Yes	0.619	0.129	4.80	2.407	0.140	17.19
Career	Farmer	–	–	–	0.487	0.230	2.12
Driving license	With license	–	–	–	−0.538	0.183	−2.94
Vehicle characteristics
Vehicle type	Motorcycle	2.884	0.115	25.08	3.289	0.179	18.37
	Pickup	−0.721	0.167	−4.32	−0.983	0.277	−3.55
	Truck	–	–	–	−0.619	0.194	−3.19
	Std. dev.	–	–	–	0.650	0.116	–
Road characteristics
Road surface	Non-dry	–	–	–	−0.593	0.187	−3.17
Traffic controls	Signal control	0.543	0.206	2.64	0.603	0.289	2.09
Other characteristics
Area	Rural	–	–	–	0.234	0.108	2.17
Time of accident	07 : 00–09 : 00	−0.593	0.210	−2.82	–	–	–
	20 : 00–24 : 00	0.388	0.137	2.83	0.581	0.186	3.12
	00 : 00–07 : 00	0.292	0.145	2.01	1.075	0.187	5.75
Crash type	Fixed object	1.609	0.197	8.17	3.053	0.206	14.82
	Pedestrian	−1.718	0.129	13.32	−2.358	0.218	−10.82
Intercept		−1.831	0.266	−6.89	−3.480	0.346	−10.06
Likelihood ratio	χ^2(48) = 3228.21;
McFadden pseudo R^2	0.348
Sample size	5138

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.