Street lights, also known as light poles, lampposts, and street lamps, are raised publicfixtures that provide illumination on the edge of a road or path when light is needed. Light-sensitive photocells are activated automatically at dusk, dawn, or at the start of dark weather. Street lights were first used in the city of Antioch from the 4th century to protect pedestrians from tripping on a path. The first widespread system of street lighting employed coal gas as the predominant source of fuel. Today, new street lighting technologies such as LED and high-intensity discharge lamps are used as beacon lights, roadway lights, and cycle path lights.