SAE J 2338

The SAE International task force on headlamp mounting height has considered the ramificaitons of reducing the maximum mounting height of headlamps on highway vehicles. The task force has concluded that it is the best interest of the driving public to make a substantial reduction in the recommended maximum height at which headlamps, particularly lower beam headlamps, may be mounted. Heights as low as 36 to 40 in (90 to 100 cm) have been considered. New tractor vehicles are in fact being designed with headlamps mounted in this range. Further recommendations were withheld in anticipation of tests to demonstrate the effect of mounting height on the legibility of certain overhead signs.