Which sign would most likely indicate roadway construction ahead?

The sign that most likely indicates roadway construction ahead is the construction warning sign. These signs are specifically designed to alert drivers about construction zones and the potential hazards associated with them, such as workers present, changes in traffic patterns, and rough road surfaces. They are typically orange with black text or symbols and serve as a clear warning to reduce speed and be prepared for changes in driving conditions.

Stop signs, yield signs, and speed limit signs serve different purposes related to general traffic control, rather than specifically indicating construction zones. Stop signs require vehicles to come to a complete stop; yield signs indicate that drivers must yield the right-of-way; and speed limit signs inform drivers of the maximum allowable speed on that stretch of road. However, none of these specifically convey the need for caution in a construction context as effectively as a construction warning sign does.