NIGHT VISIBILITY FOR OPPOSING DRIVERS WITH HIGH AND LOW HEADLIGHT BEAMS

THE RELATIVE VISIBILITY OF TWO TASKS WHICH ARE TYPICAL OF THOSE ENCOUNTERED IN THE NIGHTTIME DRIVING SITUATION WAS EXPLORED USING THE VISUAL TASK EVALUATOR MEASUREMENT TECHNIQUE. THE TASKS WERE ILLUMINATED WITH EITHER HIGH OR LOW HEADLIGHT BEAMS. AN OPPOSING VEHICLE WAS LOCATED AT ONE OF SEVERAL LONGITUDINAL SEPARATIONS WITH THE SAME BEAM CONFIGURATION AS THAT OF THE OBSERVERS TO SIMULATE A SINGLE APPROACHING VEHICLE AT ONE OF FOUR DIFFERENT MEDIAN WIDTHS. DISABILITY GLARE MEASUREMENTS WERE MADE WITH A PRITCHARD PHOTOMETER AND THE OVERALL VISIBILITY EVALUATED THROUGH AN ANALYTICAL PROCEDURE. /AUTHOR/