Final answer:
Black on orange signs on a highway identify special conditions or hazards ahead and provide specific information and directions to drivers.
Step-by-step explanation:
The black on orange signs on a highway identify special conditions or hazards ahead. These signs are typically used to warn drivers about potential dangers on the road, such as construction zones, slippery conditions, or sharp turns. They provide specific information and directions to drivers, helping them navigate through these hazardous areas safely. Some examples of these signs include 'Construction Ahead', 'Slippery When Wet', and 'Curves Ahead'.