Identifying the Factors Contributing to Injury Severity in Work Zone Rear-End Crashes

Table 2

Rear-end injury severity model results.

Variables	Fixed-parameters model			Random-parameters model
	Coefficient	t-stat	P-value	Coefficient (standard deviation)	t-stat	P-value
Young	0.566	6.577	<0.001	0.675	6.156	<0.001
Male	0.361	2.751	0.00595	0.392	2.344	0.0191
Curve	1.188	6.567	<0.001	1.529	7.069	<0.001
Heavy	0.211	2.717	0.006	0.288	3.017	0.0025
Passenger	0.358	3.559	<0.001	0.296	2.119	0.0340
Weekday	-0.773	-7.857	<0.001	-0.844	-6.99	<0.001
Daytime	-0.138	-1.759	0.07849	-0.183	-1.897	0.0578
Fog	-0.660	-6.756	<0.001	-0.988 (1.047)	-6.78	<0.001
Summer	0.303	2.797	0.00515	0.329	2.544	0.0109
Rural	0.296	3.262	0.0011	0.480	4.14	<0.001
Speeding	0.993	7.293	<0.001	1.541 ( 1.695)	6.265	<0.001
N. lane closures	0.540	4.475	<0.001	0.785	5.143	<0.001
Asphalt	0.753	6.079	<0.001	1.126	6.843	<0.001
Milling	-0.321	-2.079	0.037	-0.419	-2.335	0.0195
Threshold 1,μ1	0.558	2.44	0.0146	0.626	2.128	0.0333
Threshold 2,μ2	2.135	29.424	<0.001	2.684	20.95	<0.001
Log-Likelihood at zero	-992.5			-992.5
Log-Likelihood at Convergence	-790.5			-769.8
Number of Observations	1045			1045
AIC	1612.918			1575.51
BIC	1667.153			1664.642
McFadden Pseudo R2	0.203			0.224