Analysis of Injury Severity of Drivers Involved Different Types of Two-Vehicle Crashes Using Random-Parameters Logit Models with Heterogeneity in Means and Variances

Table 1

A summary of studies on the severity of two-vehicle crashes.

Variable names	Key findings
(a) Driver characteristics
Gender	Female drivers are more likely to be injured [13–15]. In contrast, the authors in [16] found that male drivers are more likely to sustain the probability of severe injury.
Age	Older drivers are usually more severely injured [13–15, 17–19]. However, the authors in [16] found that middle-aged drivers are more likely to sustain the probability of severe injury.
Seatbelt used	Drivers without use of safety equipment are more likely to be injured [13, 20, 21].
Alcohol involved	The alcohol involvement variable is more likely to sustain the probability of severe injury outcomes [16, 19, 20, 22, 23].
Fault status	The authors in [13] found that not-at-fault drivers are more likely to be injured. Furthermore, the authors in [18] examined and compared the effect of selected variables on driver-injury severities of both at-fault and not-at-fault drivers.
(b) Vehicle characteristics
Vehicle type	The involvement of trucks tends to increase the probability of more severe injuries [13, 22, 24]. In contrast, the authors in [14, 23] found that passenger cars are usually associated with increased injury severity.
Age of vehicle	The increased age of a vehicle is found to increase the injury severity of drivers [13–15].
Vehicle action	Some vehicle actions before the crash (i.e., left turn) significantly influence driver-injury severities [20].
(c) Roadway characteristics
Speed limit	Posted speed limit variable considerably affects the injury-severity outcomes [15–17, 21, 23, 25].
Road grade	The author in [20] found that road grade variable imposes significantly influences driver-injury severities.
(d) Environmental characteristics
Weather condition	Weather conditions (such as windy, rainy, or snowy) could significantly increase driver-injury severities [22, 24, 26, 27]. The authors in [14] found that adverse weather conditions have no similar effect.
Lighting condition	Lighting conditions are found to be significant factors influencing multiple-vehicle crashes [14, 20–22, 24].