A Comprehensive Analysis for the Heterogeneous Effects on Driver Injury Severity in Single-Vehicle Passenger Car and SUV Rollover Crashes
Table 1
Descriptions and summary statistics of variables.
Variables
Description
Passenger car
SUV
Count(percent)
Count(percent)
Response variable
Injury severity
No injury
1107(46.13)
1102(46.69)
Possible injury
515(21.46)
436(18.47)
Nonincapacitating injury
555(23.13)
584(24.75)
Serious injury
223(9.29)
238(10.08)
Discrete variables
Safety belt use
Yes
2134(88.92)
2120(89.83)
No
266(11.08)
240(10.17)
Airbag deployment
Yes
936(39.00)
627(26.57)
No
1464(61.00)
1733(73.43)
Drug or alcohol use
Yes
139(5.79)
128(5.42)
No
2261(94.21)
2232(94.58)
Failure to drive in single lane
Yes
409(17.04)
367(15.55)
No
1991(82.96)
1993(84.45)
Fatigue
Yes
205(8.54)
137(5.81)
No
2195(91.46)
2223(94.19)
Improper evasive action
Yes
446(18.58)
537(22.75)
No
1954(81.42)
1823(77.25)
Failure to control speed
Yes
324(13.50)
231(9.79)
No
2076(86.50)
2129(90.21)
Driver gender
Male
1433(59.71)
1362(57.71)
Female
967(40.29)
998(42.29)
Ejection
Yes
103(4.29)
110(4.66)
No
2297(95.71)
2250(95.34)
Vehicle action
Turning left
35(1.46)
40(1.69)
Turning right
33(1.38)
39(1.65)
Going straight
2332(97.17)
2281(96.65)
Intersection
Yes
127(5.29)
97(4.11)
No
2273(94.71)
2263(95.89)
Road class
Interstate
424(17.67)
437(18.52)
US & State highway
792(33.00)
779(33.01)
Farm to market road
495(20.63)
551(23.35)
County road
356(14.83)
355(15.04)
Others (city street, etc.)
333(13.88)
238(10.08)
Road alignment
Curve
746(31.08)
751(31.82)
Straight
1654(68.92)
1609(68.18)
Traffic control type
No control
592(24.67)
515(21.82)
Signal/stop/yield/warning sign
105(4.38)
93(3.94)
Marked lanes
930(38.75)
956(40.51)
Center stripe/divider
531(22.13)
539(22.84)
Other sign (human control, etc.)
242(10.07)
257(10.89)
Month
January
188(7.83)
174(7.37)
February
202(8.42)
204(8.64)
Marth
199(8.29)
210(8.90)
April
181(7.54)
190(8.05)
May
191(7.96)
209(8.86)
June
185(7.71)
185(7.84)
July
185(7.71)
199(8.43)
August
192(8.00)
196(8.31)
September
178(7.42)
159(6.74)
October
235(9.79)
194(8.22)
November
197(8.21)
206(8.73)
December
267(11.13)
234(9.92)
Day of week
Sunday
429(17.88)
400(16.95)
Monday
323(13.46)
317(13.43)
Tuesday
260(10.83)
289(12.25)
Wednesday
252(10.50)
271(11.48)
Thursday
280(11.67)
281(11.91)
Friday
402(16.75)
353(14.96)
Saturday
454(18.92)
449(19.03)
Time
Peak hour
441(18.38)
487(20.64)
Off-peak hour
834(34.75)
976(41.36)
Night time
1125(46.88)
897(38.01)
Rural area
Yes
1628(67.83)
1675(70.97)
No
772(32.17)
685(29.03)
Adverse weather
Yes
294(12.25)
392(16.61)
No
2106(87.75)
1968(83.39)
Road surface conditions
Wet
472(19.67)
602(25.51)
Dry
1928(80.33)
1758(74.49)
Light conditions
Daylight
1132(47.23)
1360(57.68)
Dawn/dusk
66(2.75)
54(2.29)
Night with light
329(13.73)
249(10.56)
Night without light
870(36.30)
695(29.47)
Continuous variables
Passenger car
SUV
Min
Max
Mean
S.D.
Min
Max
Mean
S.D.
Age (years)
15
97
29.600
13.339
15
87
32.014
13.984
Model year (years)
0
27
15.738
5.199
0
27
13.132
4.564
Speed limit (mph)
5
85
56.905
15.029
10
85
58.074
14.748
Note: base category; the actual vehicle model year ranges from 1990 to 2017 and the 1990 year was set as the base year, thus, the model year in Table 1 is the actual vehicle model year minus the base year (1990).
