The sign with a black half-circle and the word "Hump" is intended to advise motorists of a bump in the road, but one artist has taken the language a bit too literally and adjusted the picture to look like a man and woman lying together.
Elsewhere in Frankston, Australia, another sign advertises for graffiti removal, but part of the phone number is scribbled over with blue spray paint.
The signs are just a sampling of more than a handful of quirky sightings along Cranbourne-Frankston Road, the Frankston Standard Leader reported.
Frankston officials are looking for the mystery artist, whose careful revisions match the signs’ original aesthetic.
In one case, a resident complained about the "hump" sign to the Frankston Standard Leader but when employees arrived at the scene the next day, they found the sign had been removed, with only a pole left sticking out of the ground.
"On April 12 while driving I couldn't help but notice a blasphemous and absolutely obscene sign on the side of Cranbourne-Frankston Rd," Minnie Turner wrote in an e-mail to the Leader.
VicRoads regional director Steve Brown said: "VicRoads has arranged for them to be removed immediately and may request police to assist in identifying who was responsible."