A flagger may be necessary to alert traffic, or to stop traffic intermittently, as required by the progress of work in a work zone. The flagging operation provides protection for other workers and the public. A flagger should be alert, neat appearing and act responsibly.

The flagger’s only job is work zone protection and traffic control. The flagger must never assist the crew with work activities, or engage in any distraction, and must remain on duty until properly relieved. Use stop-slow paddles, where feasible. Flags may be used at intersections or where the back-side message is inappropriate for opposing traffic and where conditions such as high wind make the use of a paddle impractical.

Flaggers should be used in the following situations:

  • One lane is alternately used for both directions of traffic.
  • The roadway is closed for a brief period.
  • Traffic speeds need to be substantially reduced.
  • Inadequate sight distance hinders advance warning.
  • Information, such as changing conditions, needs to be conveyed to motorists.
  • Opposing traffic needs to be controlled at an intersection
  • Installing and removing other traffic control devices.
  • Where conditions require unusual precautions.


No employee is to be utilized as a flagger until the employee has shown conclusively to their Supervisor that they realize fully the importance of the job, and understands the duties and responsibilities associated with it. Flaggers shall receive training as defined in NYSDOT Standard Specifications § 619-3L1. NYSDOT provides training for its employees that meets this requirement.

Flaggers must:

  • Always face oncoming traffic and maintain situational awareness at all times.
  • Never leave their position until relieved.
  • Know where crew members and equipment are, be aware of changes, and never stand among workers and equipment.
  • Be courteous, yet professional, especially in stressful conditions.
  • Minimize conversations with motorist and pedestrians.
  • Be positioned to compensate for limited sight distance, to provide maximum advance warning, and always remain clearly visible to traffic.
  • Maintain continuous communication with any other flaggers.
  • Try to maintain color contrast with background; consider sun glare on motorist.
  • Establish eye contact with drivers to whom they must give direction.
  • Use retroreflective signaling devices during night.
  • Identify an escape path in the event of an errant vehicle
  • Have a method to alert the crew in the event of an errant vehicle.


A flagger’s activities bring them into continuous contact with the public. As they are the ones the public sees in most cases, it is important that the flaggers conduct themselves in a manner which will bring credit both to themselves and the Department. Courtesy and professionalism shall always be exercised. Even under trying conditions, a flagger should be courteous, though firm.

The flagger’s supervisor shall determine when flaggers are to be used, how many are needed, where they are to be stationed for a specific operation, and the methods of communication between multiple flaggers. Supervisors shall ensure flaggers have the appropriate tools for the conditions available on site. Supervisors shall immediately address any act that is unsafe and / or contrary applicable practices / policies and take immediate steps to correct it. Supervisors have the authority to temporarily suspend operations until the unsafe situation can be corrected. 

Traffic controllers must use the following equipment and personal protective gear:

  • Hard hat
  • High Visibility Apparel (Vest, T-Shirt or 3 Season Jacket): Must meet approved ANSI/ISEA 107-2004, Performance Class II standards. (Class III for night)
  • 24-inch stop/slow paddle, Red flag (24in by 24in). The paddle is the preferred device, but the flag may be used at intersections where the stop/slow paddle would offer contradicting information to drivers traveling in opposite directions/legs of the intersection or during incident management situations. These items must be retroreflective for use at night.
  • A red wand flashlight, if working at night, and portable lighting on the flagger station is unavailable.

Traffic Observers (Spotters)

A spotter is a person with the same qualifications of the flagger. A spotter may be required to warn workers of errant vehicles, danger from traffic, or to assist drivers of work vehicles in entering or leaving work sites or in performing U-turns.

Figure 7: Use of Hand Signaling Devices by Flaggers