Three experimental studies are described on the detection of longitudinal lead-vehicle movement in darkness. Experiment I, performed in the laboratory, isolated the relative horizontal angular motion of the lead-vehicle's taillights as a cue to the detection of relative longitudinal movement. Movement thresholds were determined as a function of initial headway, exposure duration, direction of the movement, and the presence of a background. All these factors except the last had significant effects on the movement threshold. Experiment II, also a laboratory-experiment, isolated changes in apparent size or brightness of the taillights as a cue. Movement thresholds were again found to be a function of the variables investigated in experiment I. However, thresholds now were much higher than under the isolated angular cue. It was therefore concluded that the relative horizontal angular motion of the lead-vehicle's taillights is the prominent cue in the detection of relative vehicle motion in depth. Experiment III substantiated this conclusion by confirming the parametric outcomes of experiment I under realistic night-driving conditions. The practical relevance of the estimates made from the data of two important temporal parameters in car following, viz. Time until collision and free time after detection. (A)

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,    
  • Authors:
    • Janssen, W H
    • Michon, J A
    • Harvey, L O
  • Publication Date: 1976-9


  • English

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Filing Info

  • Accession Number: 00153320
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analtyic
  • Files: ITRD, TRIS
  • Created Date: Oct 13 1977 12:00AM