I once saw a group of marketing pictures from a company that outfitted commercial trucking fleets with a ultra-violet projector lamp
The high frequency of the untra-violet light allows it to penetrate deeper into fog, snow and rain than light from the visible sectrum. Its benefits come at times of low visibility such as fog, rain or snow. It showed 2 photos, both in an environment with a simulated fog cover and visibility of 100 feet. 1 was with conventional lights, the other with conventional lights plus the UV light.
Placed at 100 feet were an orange road cone with reflecive tape, a green reflective interstate highway sign and a person wearing a white shirt and a reflective traffic vest.
In the picture with conventional light all you saw was the white glare comming from the fog. In the picture with the conventional lights plus UV light all 3 objects showed up, the road cone looked like a road flare, the sign looked like a neon sign and the person looked like a white shirt and a traffic vest hanging in mid-air.
