Warning Signs 45/ 45
California

multimedia section.

Color: Orange, black letters or symbols on.
Meaning: warns about people at work on or near the roadway and the fact that traffic can be controlled by a flag person. 

Construction Signs: These construction, maintenance or emergency operations signs are generally diamond or rectangular shaped, orange with black letters or symbols and warn you about people working on or near the roadway. These warnings include reduced speed, detours, slow moving construction equipment and lane closures.

In work areas, traffic may be controlled by a person with a sign or flag. You must obey these persons.
NOTE: Traffic fines double in work areas.

The larger sign tells you that a speed zone is ahead. The smaller sign indicates what the speed limit will be.