A High Mast Light is a raised source of High illumination lights (6~8 lights) and with high intensity on the middle of major junctions (Ring roads, Outer Ring Roads), turned on or lit automatically in the absence of light (at specified timings or at periodic times, every night).

Modern lamps may also have light-sensitive photocells to turn them ON at dusk and OFF at dawn, or activate automatically in dark weather.

The function of High Mast Light is to provide safety and guidance of traffic and to provide secure and comfortable surroundings for the travelers. It is also not uncommon for mast lights to be on posts which have wires strung between them.

High Mast Lighting plays a vital role in reducing accidents and crimes.