Objective tests of headlamps in exploitation conditions from traffic safety point of view

From many years the only exploitation activity regarding headlamps is visual aiming on the base of cut-off line. From one side there are many advanced headlamp designs with excellent performance including gas discharge devices or LED's as light source. In last few years there are many efforts towards to work out laboratory objective quality assessment methods. An example is works of technical committee CIE TC4-45. But in exploitation significant numbers of vehicles are equipped with low quality headlamps installed after repairs. Also many plastic lenses are scratched and tarnished and inside parts of headlamp are dusty. Results of this problems are not noticed during simple periodical technical inspection. In Motor Transport Institute headlight analyzer was worked out. It utilizes CCD camera and computer image analysis and allows test detailed characteristics of beam pattern in garage conditions in objective way. Using these device measurements of many vehicles in exploitation conditions was done. There was find out that significant percentage of headlamps in use does not meet minimum type approval requirements. In paper results of tests are presented and main factors responsible for difference between type approval and exploitation are described.