Table 1.

Injury severity studies of truck-involved crashes.

Authors	Truck Definition	Dependent Variable and Scale	Model	Key Findings
Duncan et al. (1998) [4]	Rigs carrying single tractor trailers	Injury severities of passenger car occupant with KABCO scales (1175 observations)	Ordered probit	Factors including dark condition, high-speed differentials, high-speed limits, grades, being in a car struck to the rear, drunk driving, and being female were found to be significant in contributing injury severities of truck-involved crashes.
Chang and Mannering (1999) [6]	A single unit or combination truck with GVWR exceeding 10,000 lb	Injury severities of most severely injured occupants with 3-level, property damage only, possible injury, and injury/fatality (17,473 vehicles)	Nested logit	Comparing to non-truck-involved accidents, factors including high-speed limits, crash occurring when making right or left turn, rear-end collision was found significant only for truck-involved crashes.
Khattak et al. (2003) [15]	Undefined	Injury severities of most severely injured occupant with KABCO scale (5163 crashes)	Ordered probit	Dangerous driving behavior, including speeding, alcohol/drug use, and non-use of restraints in single-vehicle truck crashes, significantly increased the injury severity of truck occupants.
Khorashadi et al. (2005) [10]	Trucks with GVWR over 10,000 lb	Injury severities of driver drawn randomly from crash vehicles with 4-level, no injury, complain of pain, visible injury, severe/fatal injury (17,372 vehicles)	Multinomial logit	Several factors, such as alcohol/drug use, were showed to have different influences on driver injury severity between rural and urban areas.
Lemp et al. (2011) [16]	Vehicles with GVWR over 10,000 lb	Two models: • Maximum injury severity suffered by any vehicle occupant with 4-level, no/possible injury, non-capacitating injury, capacitating injury, fatality (1894 observations) • Maximum injury severity suffered by any person involved in a crash with 3-level, non-capacitating injury, capacitating injury, fatality (922 observations)	Ordered probit and heteroskedastic ordered probit	The likelihood of fatalities and severe injury increased with the number of trailers but decreased with truck length and GVWR.
Chen and Chen (2011) [11]	Single-unit truck, tractor with a semi-trailer, and tractor without a semi-trailer	Injury severities of truck drivers with 3-level, no injury, possible/non-incapacitating injury, incapacitating injury/fatal (19,741 crashes)	Mixed logit/Random Parameters Logit	Sixteen variables were found to be only significant in single-vehicle crashes, whereas another sixteen factors were showed significance only in multi-vehicle crashes on a rural highway.
Zhu and Srinivasan (2011) [17]	Commercial vehicle weighing more than 10,000 lb	Injury severities of most severely injured occupants with 3-level, non-incapacitating injury, incapacitating injury, killed (953 crashes)	Ordered probit	Driver behavior variables, including driver distraction, alcohol use, and emotional factors, were found to have a statistically significant impact on severe injury.
Chang and Chien (2013) [12]	Vehicles with GVWR over 10,000 lb	Injury severities of the driver with 3-level, fatality, injury, and no-injury (1620 observations)	Classification and regression tree	Drunk-driving was the most detrimental factor for the injury severity of truck accidents.
Islam and Hernandez (2013) [18]	Tractor-trailer, single-unit truck, or cargo van with GVWR greater than 10,000 lb	Injury severities of most severely injured occupants with KABCO scales (8291 observations)	Random parameters ordered probit	The injury severity level was influenced by several complex interactions among factors related to human, vehicle, environment, and crash mechanism.
Islam et al. (2014) [19]	Undefined	Injury severities of most severely injured occupants with 3-level, major injury, minor injury, possible/no injury (8171 observations)	Mixed logit/Random Parameters Logit	There were differences in the influence on injury severity resulting from large truck at-fault accidents between rural and urban locations.
Pahukula el al. (2014) [14]	Undefined	The maximum level of injury sustained by the driver with 3-scale, severe injury, minor injury, no injury (11,560 observations)	Mixed logit/Random Parameters Logit	Traffic flow, light conditions, surface conditions, time of year, and percentage of trucks on the road were shown to have considerable differences in injury severity in different periods.
Naik et al. (2016) [13]	Single-vehicle trucks	Injury severities of a truck driver with 4-level, fatal/disabling injury, visible injury, possible injury, no injury/property damage only (1721 crashes)	Random parameters ordered logit and multinomial logit	Wind speed, rain, and warmer air temperature increased injury severities to single-vehicle truck crashes.
Uddin and Huynh (2017) [22]	Undefined	Injury severities of most severely injured occupants with 3-level, major injury, minor injury, possible/no injury (41,461 observations)	Mixed logit/Random Parameters Logit	Asphaltic concrete surfaces decreased the likelihood of major injuries for truck occupants during night time.
Uddin and Huynh (2018) [20]	Hazmat large trucks	Injury severities of most severely injured occupants with 3-level, major injury, minor injury, no injury (1173 observations)	Random parameters probit	Male occupants, truck drivers, crashes occurring in rural locations, dark-unlighted conditions, dark-lighted conditions, and weekdays were associated with increased probability of major injuries.
Behnood and Mannering (2019) [21]	Any medium or heavy truck, excluding buses and motor homes, with GVWR greater than 10,000 lb	Injury severities of most severely injured occupants with 3-level, no injury, minor injury, severe injury (large truck crashes in Los Angeles from 2010 to 2017, amount unclear)	Mixed logit/Random Parameters Logit	The effect of factors that determine injury severity varied significantly across time-of-day/time-period combinations.