It is illegal to dazzle oncoming drivers in Europe. Drivers from countries that keep to the left must adjust the beam pattern of their headlamps when driving in Europe. This is because in left-hand-drive vehicles the right headlight is aimed a little higher than the left so that visibility on the right side is improved. There are a number of self-adhesive headlamp converter kits available.
Only headlamps approved for use with High Intensity Discharge (HID) light sources may be fitted with HID bulbs. Because the light emitted from HID sources is stronger, the headlamps are specially designed to be self-leveling so that they do not dazzle oncoming drivers.
The Fédération Internationale de l'Automobile (FIA) recommends the fitting of daytime running lights to all new cars and the retrofit of daytime running lights to existing vehicles. A study carried out by the Federal Highway Research Institute (Bundesanstalt für Straßenwesen) in Germany found that the number of road accidents could be reduced by three percent with the introduction of such measures.
