Final answer:
A yellow and black sign of a man shoveling indicates 'Road Work Ahead.' It serves to alert drivers to potential hazards and the presence of road workers.
Step-by-step explanation:
A yellow and black sign of a man shoveling typically means Road Work Ahead. These signs are part of a group of signs designed to alert motorists of upcoming changes or potential hazards on the road. It is crucial for safety that drivers understand these signs to react appropriately. For instance, upon seeing this sign, drivers should slow down and watch for workers and equipment. This sign does not indicate a slippery road, pedestrian crossing, or a no-trespassing zone.