A STUDY ON THE LIMIT OF LIGHTING POWER DENSITY FOR ROAD LIGHTING

It is important that road lighting be designed efficiently in consideration of efficiency, light distribution, conditions for installation, and maintenance factors of luminaires. Standards regulating the maximum lighting power density of a unit area were devised to determine the efficiency of a road lighting design. The data of actual energy used in road lighting was analyzed by measuring the performances of the existing road lighting facilities in use. Since the requirements of lighting performance vary by road types and road lighting classes, standard road conditions were set up on the basis of assumed general road conditions. Energy uses per unit area were calculated according to each road lighting class and lamp used by means of computing simulation. The analysis showed that difference in energy use depends on the installation conditions, light distribution of the luminaire and various other factors. Recommended were maximum limits of energy use applicable according to the road lighting classes and the road lighting energy measured and calculated thereupon. The limited values were verified through comparing them with the energy used in actual road lighting.