title: 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.
authors.affiliation: Kentucky Injury Prevention and Research Center, University of Kentucky, 333 Waller Avenue, Lexington, KY 40504, USA. tlbunn2@uky.edu
authors.forename: T L
authors.initials: TL
authors.lastname: Bunn
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.forename: S
authors.initials: S
authors.lastname: Slavova
authors.forename: A
authors.initials: A
authors.lastname: Bathke
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data; D000328:Adult; D000367:Age Factors; D000368:Aged; D001364:Awareness; D016022:Case-Control Studies; D019992:Databases as Topic; D005260:Female; D006801:Humans; D007629:Kentucky; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D018986:Motor Vehicles; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult