The Importance of Flaggers in Traffic Control 

By Peter Kuchinsky II, CSP, CSM1, Safety

Photo by Adobe

In water and wastewater operations, there are times when activities like confined-space entry, line cleaning, inspection, maintenance, line repair, or emergency response happen in public streets or highways and need traffic control. This typically involves setting up signs, barricades, cones, and flaggers.   

When work in the public street occurs, the employer must develop and set up traffic control in conformance with the “California Manual on Uniform Traffic Control Devices,” commonly referred to as the “CA-MUTCD” or “Manual.” In many traffic control situations, flaggers are necessary to ensure worker safety and smooth traffic flow. 

A flagger or multiple flaggers may be necessary at work zones to manage traffic on public streets when cones, barricades, and warning signs are insufficient. Flaggers should be positioned at an appropriate distance before equipment or work areas to provide drivers with clear warning. This typically involves proper spacing from the work zone, placement of advance warning signs ahead of the flaggers, all in accordance with the manual, considering conditions, speed, and location.   

In most flagging situations, at least three advance warning signs may be required: Road Work Ahead, Flagger Ahead, and Prepare to Stop. 

Flaggers must wear bright, high-visibility, reflectorized warning garments, such as vests, jackets, or shirts, manufactured in accordance with the requirements of the American National Standard (ANSI) High Visibility Safety Apparel standards.  ANSI Class 3 safety vests provide the highest level of high-visibility protection, designed specifically for flaggers and workers in high-risk environments with traffic speeds exceeding 40 mph. 

During the hours of darkness, flaggers’ stations must be illuminated such that the flagger will be clearly visible to approaching traffic, and flaggers shall be outfitted with reflectorized garments. At night or in inclement weather, retroreflective material shall be visible at a minimum distance of 1,000 feet.  

Flaggers, before being assigned flagging duties, must be trained in the proper fundamentals of flagging. Stop/slow paddles and signaling directions used by flaggers must comply with the manual requirements. Additional training and instructions on flagging and traffic control must include the following: 

• Proper Flagger equipment must be used 

• Layout of the work zone and flagging station per the manual 

• Flagger knows and demonstrates the correct methods to signal traffic to stop, proceed, or slow down 

• Understands one-way traffic control and multiple flagger traffic control setups 

• Knows the procedures for allowing emergency vehicles to travel through the traffic control 

• Has the skills and temperament to handle hostile drivers and emergency situations 

Because flaggers are responsible for public safety and have the most public-facing interactions of all traffic control workers, they should be comfortable with public contact and with implementing safe practices for workers and the public. Flaggers should be able to satisfactorily demonstrate the following abilities: 

• Before being assigned flagging duties, flaggers must be trained by individuals with the qualifications and experience to effectively instruct employees on the fundamentals of flagging moving traffic. 

• Documentation of the training and skill evaluation must be maintained in the employer’s training files. 

• Best Practices for Flagging Operations 

• Flagging Stations and Advance Warning Signs set up per CA-MUTCD or manual 

• Flagger to wear a Class III safety vest for the highest level of visibility. 

• Good communications established with other flaggers via radio or visual signals 

• STOP and SLOW paddle of proper size.  

• STOP/SLOW paddles must be at least 24-by-24 inches with letters at least 8 inches high.  

• Paddle must be used with a rigid staff tall enough that the bottom of the paddle is at least six feet above the pavement 

• Be dressed neatly to reflect a good public image 

• Wear a hard hat, work boots, and safety glasses  

• Flaggers shall never turn their back on the traffic 

• Be able to warn other workers, either visually or with an audible warning device, of emergency situations or errand vehicles 

• Plan an escape route 

• Always be courteous to the public 

• Written documentation of flagger training prior to assignment of flagging duties 

Flaggers are among the most important elements of traffic control safety, serving as the first line of defense between traffic and work crews. Their importance lies in their ability to provide clear direction, detect and respond to traffic flow, distracted drivers, and work zone hazards, thereby preventing accidents and injuries for both the public and workers. 

References and Resources: 

California Code of Regulations, Title 8, Section 1599. Flaggers (www.dir.ca.gov/title8/1599.html)   

Caltrans Flagging Instruction Handbook (https://bit.ly/49DPPtI) 

Peter Kuchinsky II is a retired safety professional and risk advisor with over 25 years of service to public water and wastewater agencies, serves as a Board member on the CWEA Southern Safety Committee, and continues to provide safety training and consulting services.