Question This sign means: Answers No left turn. Flagger ahead. Two-way left turn. Turn right or go through. Explanation Regulation signs regulate traffic speed and movement, displaying rules which drivers must obey. This regulation sign means that left turns are prohibited. Take a FREE Practice Test Now This questions appears in the following tests: Colorado Practice Test Hawaii Practice Test District Of Columbia Practice Test New Mexico Practice Test Rhode Island Practice Test Oklahoma Practice Test Alaska Practice Test Iowa Practice Test New Hampshire Practice Test Washington Practice Test Maryland Practice Test Nebraska Practice Test