In the road lighting, there is a big misunderstanding about the penetration of LED street lamps for heavy fog. Most people have always believed that the penetration of LED street lights is lower than that of traditional lighting sources, which is a misunderstanding. Most people mostly see some information from the network or see some sensory feelings on the road, and do not make scientific evaluation and analysis, so that the light penetration of LED street lamps is poor. A scientific analysis of this situation will be made in this paper.
We all know that the range of visible light is between 380 nm and 780 nm, and the light in this range is acceptable and recognizable by the human eye. As shown in Figure 1
Figure 1 Spectral range of visible light
That is to say, all the lamps have the use value only in the light of this band, and the human eye is unrecognizable in this range. The analysis of penetration in this paper is also only carried out within this range. The following are the visible spectra of high pressure sodium lamps and LEDs:
Figure 2 Visible spectrum of high pressure sodium lamp (Shanghai Yaming) 
Figure 3: Visible spectrum of LED (Shanxi Guangyu Semiconductor Lighting)
It can be seen from the spectrum that the spectrum of the LED is much more comprehensive than that of the sodium lamp. The peaks of both are at 580 nm, and the blue portion of the LED only accounts for about 6% of the total luminous flux, while the sodium lamp has almost no. The red light area of ​​the LED is distributed more widely than the high pressure sodium lamp.