In order to examine how the visible distance of drivers during a car meeting changes with vertical adjustment of the headlights of the meeting car, a series of tests has been carried out. The meeting car with easily adjustable headlight in the vertical direction was stationary. The subjects drove the other car with the correctly adjusted headlights. The adjustment of the headlights was wearied at random in steps of one degree from 2 degrees too low to 5 degrees too high. The result was that compared to correctly adjusted meeting lights the visible distance was not increased, or at least nothing worth mentioning, by a downward misalignment of meeting headlights while on the other hand an upward misalignment of 1-2 degrees of meeting headlights, decreased the normal visible distance by about 25%.
Abstract