Analysis of Nonsevere Crashes on Two- and Four-Lane Urban and Rural Highways: Effects of Wet Pavement Surface Condition

Table 10

Estimated parameters for nonsevere crashes on two- and four-lane rural and urban highways using the significant variables.

Parameter	Wet-Pavement Crash			Aggregate Crash
	Estimate	Sig.	IRR	Estimate	Sig.	IRR
Constant	4.74	0.001	114.3	6.112	0.001	451
Seg. Length	0.347	0.001	1.415	0.279	0.001	1.322
AADT	0.000021	0.002	1.000	0.00002	0.001	1.000
TADT	-0.044	0.001	0.957	-0.035	0.001	0.966
Speed Limit	-0.016	0.01	0.984	-0.014	0.004	0.987
Surface Cond.
Wet=1	_	_	_	-1.624	0.001	0.197
Dry=0
Disp. Coeff.	5.23			4.00
Goodness-of-Fit Statistics
AIC	15084			21350
BIC	15117			21390
LL	-7536			-10668
Dev./DF	1.02			1.11

DF=degree of freedom.