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In the near future, the LED headlamps will be available in the market by improvement of the technique. There are some methods that can produce white light using LEDs. Probably, we think most generally method is using blue LED and yellow phosphor. But, spectral power distribution (SPD) of this type of white LED is much different from traditional white light that is produced by halogen or HID. This type of the white LED has poor spectral power in long wavelength region and much spectral power in short wavelength region. So, the white light by LED might have color-rendering problem. On the assumption that automotive head lamps with white LED and halogen, the human color perception and recognition under wide range of illuminance conditions from photopic to mesopic was measured, using categorical color naming method and elemental color scaling method. As the result of this measurement, stability of categorical color naming was lower under lower illuminance level with both light sources.

The present study was designed to investigate the advantage of a new headlamp system. This so-called smart headlamp system involves headlamps with variable beam patterns. We analytically investigated visibility for the driver and glare to other road users under several conditions including curves and straight roads. We conclude that the smart headlamp system provides overall benefits.

Headlamp aiming is one of the most important factors of lighting performance. In the U.S, visual/optically aimable headlamps must have a certain cut off vertical gradient for adjustment, and should conform to photometric requirements at its position. The manufacturer can choose a vertical cut off position either on the left side (VOL) or the right side (VOR) of the optical axis for particular headlamp system designs. However regulations aren't clearly written on headlamp aiming position on the vehicle. Even if the headlamp aiming is positioned correctly on the vehicle, the beam may cause discomforting glare to oncoming or ongoing road users, depending on the height of the lamp on the vehicle. This could also cause safety problems. The discomforting glare to oncoming drivers and the mirrors of ongoing traffic is compared between VOL and VOR of each headlamp height. This paper recommends optimum Lower-beam patterns at each headlamp height.

The goal of this study was to provide information about the frequency of installation and use of fog lamps. Two surveys were performed. In the first one, installation of fog lamps was estimated by a survey of parked vehicles in two iarge shopping centers. The second survey studied the usage of fog lamps during daytime and nighttime, under clear, rainy, or foggy conditions. In this survey, an observer in a moving vehicle noted the types of lamps that were energized on the fronts of oncoming vehicles, and whether fog lamps were installed at all. The main findings are: (1) The best estimate of the current frequency of installation of fog lamps in southeast Michigan is about 13%. (2) During daytime, the usage of fog lamps increased with deterioration in atmospheric conditions, with the usage reaching 50% of all installed fog lamps during moderate-to-heavy fog.