title: The influence of rear turn-signal characteristics on crash risk.
abstract: BACKGROUND
  The relationship between the relative risk of a rear-end collision during a turn, merge, or lane change maneuver and the characteristics of the rear turn-signal configuration was examined using crash data from seven states in the United States.
  
  
  METHODS
  Rear turn-signal characteristics-including color, optics, separation, and light source-were identified for 55 vehicle models and used in a logistic regression analysis to model the odds of a rear-end collision. Additional variables including driver demographics (gender, age), vehicle age, and light condition were also modeled. Risk was assessed using a contrast group of striking vehicles in similar collisions.
  
  
  RESULTS
  The results suggest that the odds of being the struck vehicle were 3% to 28% lower among vehicles equipped with amber versus red turn signals. Although the analysis suggests that there may be a safety benefit associated with amber rear turn signals, it is unclear whether turn-signal color alone is responsible.
  
  
  CONCLUSIONS
  The results suggest that aspects of a vehicle's rear signal characteristics may influence crash risk.
authors.affiliation: University of Michigan Transportation Research Institute, 2901 Baxter Rd., Ann Arbor, MI 48109–2150, USA. jsully@umich.edu
authors.forename: John M
authors.initials: JM
authors.lastname: Sullivan
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Flannagan
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D001334:Automobile Driving; D016009:Chi-Square Distribution; D003116:Color; D004867:Equipment Design; D006801:Humans; D008029:Lighting; D016015:Logistic Models; D018986:Motor Vehicles; D014481:United States; D014796:Visual Perception