What type of sign is used to indicate highway and street work zones?

Answer: C — Orange diamond-shaped sign

The correct answer is an orange diamond-shaped sign, which is specifically used to indicate highway and street work zones. These signs serve as a warning to drivers that they are approaching a construction or maintenance area, where conditions may change suddenly and require extra caution. Orange is the universal color for construction and maintenance areas, signaling that work is ongoing and that drivers should be prepared to reduce speed, follow detours, or navigate through potentially hazardous conditions. The diamond shape is effective for warning signs, as it captures attention and clearly conveys the message that there is a need for increased awareness due to roadwork. Other types of signs, such as green or blue, convey different messages. Green signs typically indicate directional or informational guidance, such as highway exits or mile markers. Blue signs generally provide information regarding services available to drivers. A red rectangular sign often indicates stop or prohibitory messages, not construction zones.