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Today’s discussions about high intensity discharge (HID) headlamps are often reduced to a simple discussion about glare. Glare is an important aspect when talking about the performance of automotive headlamps. It is not completely understood today and more research has to be done. Nevertheless a more “global” view may be very useful to characterize the pros and cons of HID headlamp technology. This paper describes a direct comparison of latest serial production cars with both tungsten halogen (TH) and HID headlamps. The results of the performed driving tests in real traffic and visibility distance measurements show that HID headlamps provide many benefits regarding different aspects of traffic safety. Moreover the results illustrate that drivers clearly tend to prefer HID headlamps.

The Laboratory of Lighting Technology at the Technische Universität Darmstadt has conducted experiments to verify whether the prevalently reported different glare strains of the three light sources in automotive lighting, namely tungsten halogen lamps, high intensity discharge lamps and LEDs, can be verified in real traffic geometry. Furthermore, these light sources will be used for new adaptive driving beam functions. These systems will alter the conventional cut-off lines or simply switch off sectors where other road users have been detected. It is therefore probable that these other road users will experience more glare illuminance than they would, if the oncoming car would be equipped with a well aimed classical passing beam. The tests take place on a former air field now used as the university’s testing site. Apart from the glare sources no other visual disturbances are present. The geometry of the test setup is chosen to represent a real traffic situation.