Headlamps vertical aim is analysed and discussed in relation to its effects on driving safety during nighttime conditions. The legal requirements in Europe, the U.S. and Japan are strictly dependant on the beam pattern as specified by relevant regulations, but enforcement is often questionable. Progress in lighting technologies may adversly influence the consequences of vertical misaim.
This study was designed to identify the causes of misaim, with separate evaluation of human factors and wear during operation of the vehicles. The consequences are divided into two parts (a) for the driver himself and (b) for the other road users.
The ise of levelling devices is an approach to improving the accuracy and consistency of vertical aim. The automatic versions eliminate the possibilities of misuse, and the most advanced quick-response devices resolve the problem of transient positions due to vehicle acceleration and breaking.