Duties of Flaggers
Flaggers are one of the most visible and vital members of the traffic management team. They act as the human link between drivers and the construction crew, ensuring that vehicles move safely through or around work zones while protecting workers and equipment from harm. Because they operate in direct contact with live traffic, flaggers must be alert, disciplined, and fully trained in their duties.
Flagging operations must always comply with OSHA 29 CFR 1926 Subpart G and the Manual on Uniform Traffic Control Devices (MUTCD). These standards establish how flaggers perform their work, what equipment they use, and where they stand in relation to the roadway.
The Primary Role of a Flagger
The primary role of a flagger is to provide clear, positive guidance to motorists and construction vehicles. A flagger’s signals must command respect, prevent confusion, and ensure that drivers react safely and predictably. Their duties include:
- Controlling vehicle flow using STOP/SLOW paddles or approved flags.
- Protecting the work crew by stopping traffic when necessary.
- Providing drivers with advance warning of hazards or lane closures.
- Directing construction vehicles in and out of the work area.
- Monitoring traffic queues and reporting unsafe driver behavior.
- Maintaining communication with other flaggers and the supervisor.
Every movement a flagger makes must be intentional and easily understood by drivers traveling at highway speeds.
Positioning and Visibility
A flagger must be positioned where they are clearly visible to approaching drivers at all times. They should stand on the shoulder of the road or a designated safe area, never directly in the travel lane, unless absolutely necessary for emergency control.
Key placement considerations include:
- Standing far enough in advance of the work area to give drivers time to react.
- Facing oncoming traffic at all times.
- Maintaining a firm stance with an unobstructed escape route.
- Avoiding standing near equipment, parked vehicles, or visual distractions.
- Relocating when sun glare or shadows reduce visibility.
Flaggers must never turn their back on traffic. Continuous awareness of approaching vehicles is critical for survival.
Required Equipment and PPE
Flaggers must wear and maintain all required high-visibility and protective gear. The ANSI/ISEA 107 standard defines the color and reflectivity requirements for this apparel.
Minimum PPE requirements include:
- High-Visibility Vest or Shirt: Fluorescent orange, yellow, or lime, Class 2 for daytime and Class 3 for nighttime or low-light conditions.
- Hard Hat: Brightly colored and reflective when required by site policy.
- Safety Boots: Steel or composite toe, non-slip soles.
- Gloves: High-visibility or reflective, when used for signaling or hand protection.
- Eye Protection: To guard against dust and debris from nearby work.
- Flashlight with Red or Orange Wand: Required for night flagging.
Clothing must be kept clean to maintain reflectivity, and vests should be fastened properly so reflective strips form a continuous visible pattern.
Equipment for Flagging Control
Flaggers use specific devices to communicate with drivers. The preferred device is the STOP/SLOW paddle, which is an octagonal sign mounted on a staff, red on one side with “STOP” and orange or yellow on the other with “SLOW.”
- The paddle must be at least 18 inches across with 6-inch lettering.
- Flags (24 inches square, red cloth on a staff) are used only when paddles are not available or during emergency situations.
- Cones, barricades, and advance warning signs must always support flagger operations.
At night, paddles or flags must be accompanied by proper lighting—flashlights with orange or red wands are required for visibility.
Standard Hand and Paddle Signals
All flaggers must use standard, uniform signals so motorists can immediately recognize and respond:
- To Stop Traffic: Hold the paddle with the “STOP” side facing the driver and the free hand raised with the palm toward traffic. Stand facing the lane being stopped.
- To Proceed Traffic: After ensuring it is safe, turn the paddle to the “SLOW” side and motion drivers forward with the free hand.
- To Alert Traffic to Slow Down: Hold the “SLOW” side toward traffic and move the free hand in a slow, sweeping motion.
Movements must be deliberate, steady, and never abrupt. Never wave drivers through casually; all signals must be professional and consistent.
Communication Between Flaggers
When two flaggers are controlling opposing traffic directions, coordination is essential. They must be able to see each other directly or maintain radio communication at all times.
Procedures include:
- Agreeing on a common system of radio calls or hand cues before starting work.
- Confirming that one direction is completely stopped before allowing the opposite side to proceed.
- Avoiding simultaneous releases of traffic in both directions.
- Keeping radio communication short, clear, and free of chatter.
If line-of-sight is lost, an additional flagger or spotter may be required to maintain control safely.
Conduct and Professionalism
Flaggers represent the construction project to the public. A calm, courteous, and professional demeanor builds trust and prevents confrontations.
Flaggers must:
- Stay alert at all times—no cell phones, music, or distractions.
- Avoid casual conversation while on duty.
- Never lean on vehicles, equipment, or signs.
- Refrain from smoking, eating, or other activities that reduce attention.
- Treat motorists respectfully, even when they are impatient or hostile.
When a driver becomes aggressive, do not engage or argue. Note the vehicle description and plate number if possible, and report it to the supervisor or law enforcement immediately.
Environmental and Site Conditions
Flaggers must adjust to changes in visibility and weather. During heavy rain, fog, or snow, visibility decreases and stopping distances increase. To maintain safety:
- Increase the distance between the flagger station and the work area.
- Add additional warning signs or flashing beacons if required.
- Use extra lighting at night and ensure all reflective surfaces are clean.
- Rotate flaggers more frequently to prevent fatigue during extreme heat or cold.
Heat, cold, or fatigue can reduce reaction times. Supervisors must monitor flaggers for signs of exhaustion or reduced alertness.
Entry and Exit of Construction Equipment
Flaggers also play a key role in coordinating construction vehicle movements. When trucks or equipment enter or leave the work area:
- Stop traffic in both directions when necessary.
- Make eye contact with the driver of the equipment before signaling.
- Use clear hand or paddle signals to indicate when it is safe to proceed.
- Resume normal traffic flow only after the equipment is fully clear of the roadway.
This coordination helps prevent collisions between motorists and heavy machinery.
Emergency Procedures for Flaggers
Flaggers must always be prepared for emergencies such as collisions, driver confusion, or vehicles entering the work zone.
Steps to follow:
- Move to a safe location immediately—protect yourself first.
- Alert nearby workers and stop all traffic.
- Notify the site supervisor or call emergency services.
- Provide accurate information about location, direction of travel, and number of vehicles involved.
- Keep bystanders and workers clear until help arrives.
Do not attempt to stop a runaway or out-of-control vehicle. Always prioritize personal safety and quick communication.
Key Principles of Effective Flagging
- Be visible, predictable, and professional at all times.
- Follow the Traffic Control Plan exactly as written.
- Coordinate with other flaggers and the site supervisor.
- Keep an escape route planned and clear.
- Never abandon the flagging post without proper relief.
Flaggers are often the first and last people drivers see as they pass through a construction zone. Their performance directly reflects the safety culture of the entire project. Proper flagging saves lives, prevents accidents, and keeps work zones compliant with OSHA and MUTCD requirements.