Tenn. Code Ann. § 55-9-407: Multiple beam road lighting equipment - Use

Whenever the road lighting equipment on a motor vehicle is so arranged that the driver may select at will between two (2) or more distributions of light from headlights or lamps or auxiliary road lighting lamps or lights, or combinations thereof, directed to different elevations, the following requirements shall apply while driving during the times when lights are required:

(1) When there is no oncoming vehicle within five hundred feet (500'), the driver shall use an upper distribution of light; provided, that a lower distribution of light may be used when fog, dust, or other atmospheric conditions make it desirable for reasons of safety, and when within the confines of municipalities where there is sufficient light to render clearly discernible persons and vehicles on the highway at a distance of five hundred feet (500') ahead and when following another vehicle within five hundred feet (500'); and

(2) When within five hundred feet (500') of an oncoming vehicle, a driver shall use a distribution of light so aimed that the glaring rays therefrom are not directed into the eyes of the oncoming driver.