Maintenance factors occurred by the aging or pollution of the led street lighting. It is the multiplier that expresses the decrease in light output. The maintenance factor refers to the loss of light that occurs over time and is also known as the loss factor. During the operating time of light sources, there can be a slight decrease in light output. In addition to this, pollution of light sources can also cause decreasing of light output. When calculating lighting levels, this decrease from aging and pollution should be taken into consideration.