What sign must be placed before beginning a flagging operation?

The sign that must be placed before beginning a flagging operation is "Flagger ahead." This sign is essential for alerting drivers that they will encounter a flagging operation soon, which involves a flagger directing traffic in the work zone. The presence of this sign helps to prepare drivers for potential stops or directional changes instructed by the flagger, ensuring that they approach the area with caution and awareness.

The placement of the "Flagger ahead" sign is particularly important for improving safety for both drivers and workers in the work zone. By giving advance notice, it allows motorists to adjust their speed and prepare for any actions they need to take, such as following the flagger’s directions or navigating around obstacles.

Other signs serve different purposes but do not specifically indicate the presence of a flagger. For example, "Detour ahead" provides information about alternate routes, while "Road work ahead" indicates that construction or maintenance is taking place in the area but may not explicitly inform drivers about a flagging operation. "Flagger in sight" is typically used when the flagger is already present and visible to drivers, rather than as a preemptive warning. Hence, "Flagger ahead" is the correct choice to ensure proper communication about the upcoming flag