What is a traffic control device?

• A. A parked car with hazard lights.
• B. A sign, marking or machine placed on the roadway to regulate, warn or guide traffic.
• C. A billboard along the roadway.
• D. A traffic cone that is not in use.

Answer: (B)

A traffic control device is any sign, marking, or machine placed on or near the roadway to regulate, warn, or guide traffic. These devices come from authorities to help manage the flow of vehicles and pedestrians, reduce crashes, and convey important information such as speed limits, lane usage, or hazards. Examples include regulatory signs (stop, yield, speed limit), warning signs (curves, intersections), road markings (centerlines, crosswalks, arrows), and active devices like traffic signals or flashing beacons. The other options don’t fit because a parked car with hazard lights isn’t an official device used to control traffic, a billboard is advertising not guidance, and a cone that isn’t in use isn’t currently regulating traffic.