The girl had been reported missing by her parents in North Carolina on Tuesday morning, and was spotted inside a car in Kentucky two days later.
The 16-year-old used the gesture designed to help domestic abuse victims ask for help to alert a passing driver.
Authorities say they arrested a 61-year-old man.
A driver called police after noticing "a female passenger in the vehicle making hand gestures that are known on the social media platform TikTok to represent violence at home - I need help - domestic violence," the Laurel County Sheriff's Office said in a statement.
The girl, who has not been named, told officers she had travelled through North Carolina, Tennessee, Kentucky, and Ohio.
Police later arrested James Herbert Brick, 61, of Cherokee, North Carolina, while he was driving near a Kentucky interstate on Thursday afternoon.