What is the first part of a traffic control zone?

The first part of a traffic control zone is typically the warning signs. These signs are essential for alerting drivers to the presence of upcoming changes in traffic conditions due to construction, maintenance, or other potential hazards. The purpose of warning signs is to provide advance notice so that drivers can prepare to adjust their speed and behavior accordingly, thus enhancing safety for both road users and workers in the vicinity.

While cones and barriers serve to delineate the actual work area and traffic signals may control the flow of traffic, neither of these elements is as fundamental to the initial communication of hazard as warning signs are. Work zone markers also play a role in directing traffic through or around construction zones, but they generally come after the initial warnings have been established to guide driver behavior appropriately.