What does the yellow light signify on a construction vehicle?

The yellow light on a construction vehicle signifies a warning that the vehicle is in operation. This is an important safety feature designed to alert other drivers and pedestrians that the vehicle is active and may pose a potential hazard. The use of a yellow light is universally recognized as an indicator of caution, making it clear that caution should be exercised around the moving vehicle.

This warning system is crucial in construction zones where vehicles may maneuver in unpredictable ways or be preparing for tasks that could impede traffic flow or visibility. By ensuring that the yellow light is operational, the vehicle communicates its presence effectively, helping to prevent accidents and improve overall safety in the work zone.

The other options describe different functions or meanings that are not aligned with the role of a yellow light, focusing instead on features such as vehicle availability, permission to proceed, or alerts for roadblocks, which do not accurately define the function of the yellow light in this context.