Factors affecting the performance of foglamps are described. While foglamps usefully provide an increased side spread to help drivers steer a course along a road, they do not increase the reduced visual range of the driver. A simulation program was developed to calculate the luminance distribution in fog situations during night-time driving. Calculations are presented of stray light luminance, the effect of stray light above the cut-off line and the influence of the position of the cut-off line. An investigation in real scenery was conducted on a closed road at night with a calculated fog luminance on a head up display overlying the illuminated scenery in front of a car. Recommendations and a proposal for a fog headlamp light distribution are presented. For the covering abstract see ITRD E123380.
Abstract