Table 4: Multinomial Logistic Estimate of barrier crashes, Interstate system crashes.

Variables Serious Crashes Minor Crashes
Coefficient Odds Ratio P-value Coefficient Odds Ratio P-value
Intercept -4.3555 <.0001 -1.5981 <.0001
Type of barrier (Reference: others) Concrete 0.0574 1.059 0.8610 0.4269 1.533 0.0007
Cable -1.4343 0.238 <.0001 -1.0637 0.345 <.0001
Road condition (Reference: dry) Wet 0.0985 1.103 0.7797 0.0595 1.061 0.7117
Snow -1.4675 0.230 0.0188 -0.7104 0.491 0.0002
Slush -1.5894 0.204 0.1239 -0.6452 0.525 0.0152
Ice -1.1137 0.328 0.0006 -0.5042 0.604 <.0001
Driver characteristics Age: <35 (Reference:>=35) 0.8716 2.391 0.0002 0.0949 1.100 0.3041
Gender: Male (Reference:female) -0.3552 0.701 0.1436 -0.6421 0.526 <.0001
Drive action Driver condition: non normal (Reference: normal) 1.4458 4.245 <.0001 0.6403 1.897 <.0001
Front head collision -0.0259 0.974 0.9126 0.2869 1.332 0.0022
Negotiating a curve (Reference: others) 0.5627 1.755 0.0374 0.2079 1.231 0.1029
Roll over 2.5057 12.252 <.0001 1.8960 6.659 <.0001
Driver was improperly restrained:yes (reference=no) 1.6077 4.991 <.0001 1.0005 2.720 <.0001
Driver alcohol citation record: yes (reference: no) 0.3124 1.367 0.4056 0.6363 1.889 0.0033
Driver had an improper driver action:yes (reference: no) 1.6077 1.453 <.0001 1.0005 1.300 <.0001
Speed limit was not complied (Reference: speed limit was compiled) 0.8734 2.395 0.0040 -0.1024 0.903 0.5632