title: Car backlight position and fog density bias observer-car distance estimates and time-to-collision judgments.
abstract: OBJECTIVE
  A series of experiments assessed biases in perceived distance that occur while driving as a function of the backlight position of the car ahead and fog density.
  
  
  BACKGROUND
  V. Cavallo, M. Colomb, and J. Doré (2001) have shown that smaller horizontal backlight separation and fog may result in increased estimates of the distance between an observer and a car of which only the backlights are visible. They also predicted that raising the height of the car backlights would lead to increasing distance estimates.
  
  
  METHODS
  Distance perception was assessed in both static and dynamic computer-simulated scenarios in which the distance estimates were performed using a familiarized analog scale or using time-to-collision judgments for both pairs of backlights and single backlights.
  
  
  RESULTS
  In a series of five experiments, the horizontal separation and fog density effects were replicated. In addition, distance estimates were consistently larger with higher than with lower vertical backlight positions.
  
  
  CONCLUSIONS
  There is reason to believe that biases in distance perception may be augmented by car backlight positions and by low-visibility weather conditions.
  
  
  CONCLUSIONS
  Car designers should take backlight placement seriously. Speed-dependent car-to-car distance control systems seem desirable to counteract biases in distance perception.
authors.affiliation: Department of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany. axel.buchner@uni-duesseldorf.de
authors.forename: Axel
authors.initials: A
authors.lastname: Buchner
authors.forename: Martin
authors.initials: M
authors.lastname: Brandt
authors.forename: Raoul
authors.initials: R
authors.lastname: Bell
authors.forename: Judith
authors.initials: J
authors.lastname: Weise
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D001336:Automobiles; D005260:Female; D005858:Germany; D006801:Humans; D007600:Judgment; D008029:Lighting; D008297:Male; D008875:Middle Aged; D019370:Observation; D013037:Spatial Behavior; D014887:Weather