This sign means:

Do not enter.
Stop ahead.
Roadwork or maintenance is present.
The Correct Answer and Explanation is :
The sign in the image indicates “Roadwork or maintenance is present.”
Explanation:
This sign is a warning sign meant to alert drivers, particularly motorcyclists, that roadwork or maintenance activities are taking place ahead. These signs are used to ensure the safety of both workers and road users by providing them with an advance notice of potential hazards or delays on the road.
In Illinois, as in many other states, signs indicating roadwork or construction zones are typically diamond-shaped with orange or yellow colors. These colors are highly visible, especially in low-light conditions, and are used to draw attention to the fact that something on the road is not normal. Such signs are part of the larger set of traffic control devices that help guide and inform drivers about the road conditions, ensuring smoother and safer travel.
When you see this sign, you should slow down and stay alert for possible changes in road conditions. These changes could include narrower lanes, rough road surfaces, construction vehicles entering or exiting the road, or even workers being present on or near the roadway. It’s also important to watch for other signage that may indicate detours, lane closures, or reduced speed limits, as these may be in effect while work is ongoing.
Failure to heed these warnings can result in accidents or traffic violations, as construction zones are often areas with high risks for both workers and drivers. By staying cautious and following the instructions on the signs, you help ensure the safety of everyone involved, including construction workers, fellow road users, and yourself. Always drive carefully through roadwork areas, respecting any detours, reduced speed limits, or lane changes.