Traffic control devices signal that a work zone is ahead. These devices tell drivers where they are, where they are going and how to get there. Traffic control devices communicate their message in several ways, by color, shape, words, symbols and placement to provide information. Following traffic control devices can be used to ensure road work safety -  - Signs - Cones - Drums/Barrels - Barricades - Concrete barriers In transition areas, more robust vehicle-mounted traffic control devices may be used, such as arrow boards, portable changeable message signs, and high-intensity rotating, flashing, oscillating, or strobe lights, instead of channelizing devices.