Fog Lamps in Clear Weather Approximately 64.5% of drivers in cars with fog lamps use their fog lamps at night in clear-weather conditions not warranting fog lamp use. Fewer drivers (60.6%) use their fog lamps in moderate-to-heavy fog conditions warranting fog lamp use. This indicates that drivers tend to use fog lamps to supplement their low beam headlamps, rather than as an aid to poor-weather visibility. (Sivak et al. 1997). Assuming the lamps in question at least approach the general character of a fog beam, providing primarily foreground illumination and lateral spread, the indication is that drivers want more and wider foreground illumination. They get it by using fog lamps. US low beams have traditionally had less and narrower foreground illumination than comparable ECE low beams primarily due to concern that excessive foreground illumination will limit distance vision by drawing the drivers visual attention to the foreground or by reducing the drivers level of dark adaptation. This may not be the case. Olson and Sivak (1983) studied driver eye movements at night as a function of foreground illumination. At high levels of foreground illumination, drivers tended to look further down the road. Olson & Sivaks interpretation is that with high levels of foreground illumination, drivers tend to use peripheral vision for the foreground and foveal vision for distant points. This may be why drivers prefer higher levels of foreground illumination than is traditionally provided by US low beams. Automotive lighting engineers have noted they have been asked to design original-equipment fog lamps explicitly to fill the black hole on the road in front of the car. If, as seems to be the case, more and wider foreground illumination is not harmful and may be beneficial to safety, then it is better to encourage or require more and wider foreground illumination from regulated and controlled low beam headlamps than to leave this function to unregulated and frequently-misused devices with a high capacity to create excessive glare.