​Defines the essential requirements and precautions for ensuring satisfactory results and economy in street lighting. It embraces all classes of streets and lanes, and the economic limitations in the lighting of relatively unimportant streets have been considered. The recommendations of This code for the different classes of streets with regard to spacing, mounting height and location of lighting units are given for straight level roads. Special conditions such as curves, grades, intersections, etc., will always require special treatment to fulfil the general principles herinafter stated.