The Effects of Semi Truck Driver Age and Gender and the Presence of Passengers on Collisions with Other Vehicles

Abstract

Objective: A retrospective population-based case control study was conducted to determine whether semi truck driver age and gender and the presence of passengers affect the likelihood that a semi truck driver will be at fault in a semi truck collision (STC) with another vehicle.

Methods: Cases were identified as semi truck drivers in at-fault STCs with other vehicles and controls were semi truck drivers in not-at-fault STCs with other vehicles, using the Kentucky Collision Report Analysis for Safer Highways (CRASH) electronic database from 2000–2006. Multiple logistic regression was performed.

Results: The results from the final multiple logistic regression show that solo semi truck drivers, aged 65 and over, were the age group at highest risk for at-fault STCs with other vehicles. However, the presence of passengers in the semi truck had a protective effect for semi truck drivers aged 65 and older. When controlling for all other variables in the model, female semi truck drivers were at higher risk than male drivers, and curvy and graded/hillcrest roads increased the odds that the semi truck driver would be at fault in an STC with another vehicle. Daytime driving and driving on roads with low posted speed limits (35 mph and less) were associated with a higher probability of being at fault in an STC with another vehicle.

Conclusions: The results of this study have the potential to inform public policy in regard to the presence of passengers and their positive protective effect on older (aged 65 and older) semi truck drivers, particularly in long-distance driving performed by solo semi truck drivers vs. team semi truck drivers.

Keywords:

• Passengers
• Semi trucks
• Older semi truck driver
• Case control
• At fault
• Age

ACKNOWLEDGEMENTS

The authors are grateful to Dr. Julia Costich for helpful comments on the manuscript and to the Kentucky State Police for supplying the data for this study. This work was supported by Grant/Cooperative Agreement Number 2U60OH008483-04 from NIOSH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of NIOSH.

Notes

^a Percentages may not total to 100 percent due to rounding.

^a Fisher's exact test is used due to small cell counts.

^a Adjusted odds ratio is the ratio of the odds for a semi truck driver from the exposed group to be at fault versus the odds of a semi truck driver from the reference group to be at fault when all other factors are the same.

^b 95 Percent confidence interval.

^c Interactions reflect the effect of one variable (passenger presence) depending on the other variable (age group).

∗Indicates p < 0.05.