Tennessee Code Title 4. State Government § 4-3-2316

(a) As used in this section, “family restroom” means a separate, fully enclosed restroom that:

(b) If a rest area or welcome center has a family restroom, then the department of transportation shall install a sign or marker displaying a symbol or language indicating the accessibility of a family restroom to motorists, or include that symbol or language on an existing rest area or welcome center sign or marker, on the portions of the interstate system and state system of highways and associated rights-of-way near the rest area or welcome center.

(c) The department may consult the departments of safety and tourist development in manufacturing and installing the signs or markers or designating or placing symbols or language on signs or markers pursuant to this section.

(d) Symbols, language, signs, and markers installed pursuant to this section must be consistent with the Manual on Uniform Traffic Control Devices (MUTCD) and the state supplemental guidelines, as applicable.

(e) The department shall post on its website the rest areas and welcome centers that have family restrooms.

(f) In consultation with the departments of safety and tourist development, the department of transportation is authorized to promulgate rules necessary to effectuate this section.  The rules must be promulgated in accordance with the Uniform Administrative Procedures Act, compiled in chapter 5 of this title.