Abstract
Measurements were made in field experiments on a test track about visibility distances with both high and dipped beam of halogen and wolfram lamps, with and without opposing vehicle lights. Dipping distances and obstacle reflectance, also on wet roads, were equally measured. It is shown that small occasional differences in headlight aiming etc. cause larger differences in visibility than the light system. Under real condition these effects should be even larger. Halogen bulbs improved visibility on low beam, but still was too short.