Which control device does the Manual on Uniform Traffic Control Devices (MUTCD) describe for establishing work areas?

The Manual on Uniform Traffic Control Devices (MUTCD) provides comprehensive guidelines for various traffic control measures, including those used for establishing work areas. The reference to traffic control devices encompasses all forms of signs, signals, barriers, cones, and other items designed to manage traffic flow and ensure the safety of both workers and motorists in work zones. By identifying this choice as the answer, it underscores the importance of a wide range of tools that fall under the category of traffic control devices, which are essential for effective traffic management in work areas.

In contrast, while traffic lights, flares, and traffic cones each serve specific purposes in managing vehicular movement and alerting drivers, they are not as encompassing as the broader term used in the correct answer. Traffic lights are mainly for directing traffic at intersections, flares are temporary warning devices, and traffic cones are used primarily for short-term barriers or channeling traffic. Therefore, the clarity and breadth of "traffic control devices" offers a more comprehensive understanding of how work areas are established and maintained effectively.