Today, traffic accidents and the resulting damages are one of the major problems of road transportation in the country. The need to control these incidents in order to prevent accidents as much as possible and as a result to reduce many human and financial losses is fully felt. One of the important parameters on traffic accidents on the country's roads is road lighting. Moonlight brightens the road surface and increases drivers' visibility and sense of security, which can be considered as the positive effects of moonlight on reducing accidents. The purpose of this research is to investigate the effects of the moon on the number of road accidents during moonlit nights. A number of 9 out-of-town highways from Kerman, Kermanshah and Kurdistan provinces were used as a case study in this research, and the accident data of these 9 highways in the years 1996 to 1998 were used to compare the effect of moonlight on moonlit nights and at night. Non-moonshine was used. The result showed that with the increase of the crescent moon or the increase of the moonlight, accidents with damage, injury and death all decrease significantly. In general, by comparing the correlation of the crescent moon variable and the total number of accidents that happened at night, it shows that with the increase of the crescent moon, the total number of accidents decreases by -0.631.