Md. Code, Transportation § 8–655

(a) The Administration shall post the National Human Trafficking Resource Center Hotline information sign described in § 15–207 of the Business Regulation Article in each restroom at a rest area within the right–of–way of an interstate or State highway.

(b) A sign required under this section shall be posted:

(1) On the inside of each stall door in the restroom; or

(2) On the back of the door at the entrance to the restroom.