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It is frequently the case that pilot/escort vehicle operators (P/EVO) may need to control traffic during the movement of oversize loads. Equipment and procedures for flagging traffic are somewhat standardized from State to State; however, the authority for P/EVOs to control traffic is not consistent across States. Further, when controlling traffic in a temporary situation (known as temporary traffic control or TTC), P/EVOs face a particularly dangerous situation in part because the flagger does not have the advantages typically found in other traffic control situations, such as construction work zones.

Unlike construction zones, there are no advance warning signs (Flagger Ahead, or One-Lane- Road signs, for example) for P/EVOs. TTC zones "present constantly changing conditions that are unexpected by the road user. This creates an even higher degree of vulnerability for the workers and incident management responders on or near the roadway," according to Manual on Uniform Traffic Control Devices (MUTCD)2 Section 6D.03. The lack of advance warning devices, combined with the unpredictability inherent in moving oversize loads, produce additional risks for flaggers in TTC situations.

For these reasons, it is vital the flagger be positioned so that he/she will be seen by motorists. Several factors affect where the flagger should be located. First, how fast is traffic moving? The P/EVO must consider stopping distances based on how heavy a vehicle is, how fast it is moving, whether it is on a down slope or not, whether the roadway is gravel or asphalt, wet or dry. When considering the position for the flagger, consider how long it will take for the largest, heaviest, fastest moving vehicle that may approach the flagger to stop, and place the flagger in a position that allows adequate stopping distance for that vehicle.


States typically require P/EVOs to carry a STOP/SLOW paddle and wear safety apparel (for example, hard hats, retroreflective apparel, etc.). Depending on the laws of each State, P/EVOs may be involved in both planned and unplanned traffic control situations. A typical planned flagging situation would be when a wide load requires narrow bridges be closed to other traffic. An example of an unplanned situation would be when the load vehicle breaks down or the load shifts. It is important to keep in mind that even if the P/EVO is escorting a load that moves only during daylight, this does not mean the P/EVO won't be flagging traffic after dark, especially in the event that the load becomes disabled.


When the need to control traffic arises (for example, to get around an obstruction on or near the roadway or on a narrow bridge), make and follow a plan for how the team intends to go about getting traffic stopped before the load approaches the narrow bridge, makes a turn, or performs other maneuvers that involve encroaching on other lanes of traffic.

In summary, conditions to be considered when deciding where to place a flagger may include how fast traffic is moving, features of the terrain, and the condition and type of roadway surface. Other considerations may include weather, light conditions, and traffic volume.


  1. A STOP/SLOW paddle of at least 18" x 18" with a reflective surface is required [2009 MUTCD Section 6E.03]. The paddle must be octagonal, and the STOP face must be red with white letters, while the SLOW face must be orange with black letters. It is also advisable to have a 24" STOP/SLOW paddle for higher speed roadways where traffic is moving at more than 60 mph. A 7-foot pole for mounting the STOP/SLOW paddle should be available for situations in which traffic may need to be controlled for longer than 10 to 15 minutes. Some States require the P/EVO to carry an extra paddle because load drivers are not required to carry one, and most collisions happen at intersections where more than one lane of traffic may need to be controlled.
The STOP/SLOW paddle may be modified to improve conspicuity by incorporating either white or red flashing lights on the STOP face, and either white or yellow flashing lights on the SLOW face. The flashing lights may be arranged in any of several patterns. (See MUTCD Section 6E.03 for details on light placement and other specifications.)
  1. Hardhats should comply with American National Standards Institute (ANSI) requirements and/or requirements of the States. Type II hardhats (as required by the States) are recommended for P/EVOs because they reduce the force of impact from off-center, the side, or the top of the head. These types of impact may result from contact with any protruding part of a load. The hardhat for the P/EVO is also used to increase visibility when flagging traffic.
  2. Safety vests are required for flaggers and others involved in roadside operations, and according to the MUTCD Section 6D.03 High-Visibility Safety Apparel Standard, they must meet ANSI Performance Class 2 or 3 requirements for daytime and nighttime activity. The background (outer) material color should be fluorescent orange-red, fluorescent yellow-green, or a combination of the two, with similarly colored retro- reflective material visible at a minimum of 1,000 feet.
  3. Many States also require P/EVOs to carry a 24" x 24" red flag (or red-orange or fluorescent versions of those colors) for controlling traffic in an emergency when no STOP/ SLOW paddle is available. At no time is the flag (or a STOP/SLOW paddle) to be held outside the window of a moving vehicle in an effort to stop traffic.
  4. Reflective cones and/or triangles are required by many States. At least three bi-directional emergency reflective triangles are recommended even in States that may not require them. Some States require traffic cones of various sizes, and still others require the P/EVO to carry flares. With respect to truck drivers, the Federal Motor Carrier Safety Administration allows these warning devices to be used in addition to triangles, but not in lieu of them. Placing a cone or triangle across the lane being controlled helps motorists know exactly where the flagger wants the car to stop and also provides an extra measure of safety for the flagger.
  5. P/EVOs should carry at least one operating flashlight/traffic wand equipped with a safety nose cone. The light should be LED and visible for 500 feet. The wand should be impact and water resistant and have a non-slip handle. The on-off switch should be visible night or day. P/EVOs should carry extra batteries and bulbs.
  6. Communicating accurate information in time to respond to hazards is central to safe operations. Two-way radios, compatible with those of the load driver and other P/EVOs on the team, and capable of transmitting and receiving signals for at least ½ mile are required by most States. In spite of leaps in sophistication and capabilities of personal communication devices, including smart phones, CB radios remain the best communication equipment for the load movement team.

In the same way that drivers should drive defensively, so should flaggers remain alert and ready to act defensively. Flaggers should be handling no other devices, and other workers should not congregate near the flagger to avoid causing a distraction. The flagger should not be positioned near other vehicles and must not block egress in any direction. The flagger must keep focused on approaching traffic at all times.


Flagging control, as prescribed in the 2009 MUTCD, Chapter 6E, shall be followed. The flagger should stand either on the shoulder adjacent to the road user being controlled or in the closed lane prior to stopping road users. Flaggers must be in the standard position (right shoulder of lane being controlled), the place motorists are used to seeing stop signs. The flagger must use standard equipment (STOP/SLOW paddle, same shape and colors as all other stop signs), at the standard height (7-foot pole, so the paddle is at the same height as other signs) and wear standard safety gear (hardhat, safety vest) to control traffic. Standardization is a matter of safety, especially when drivers are being required to stop.

The flagger must display the STOP/SLOW paddle in the place drivers typically see signs. This is an important example of standardization that enhances safety for the motoring public and the load movement team. Motorists do not look for stop signs in moving vehicles. Flagging traffic involves getting out of the vehicle.

As mentioned, the flagger should (or as required by the States or MUTCD Part 6E.07) not attempt to control traffic from a moving or stationary vehicle, or by parking a vehicle across lanes of traffic, especially at highway speeds. This behavior is exceedingly dangerous and irresponsible. One of the first rules new drivers are taught is to never, ever stop in a roadway. P/EVOs are not authorized to break any traffic laws, and this includes parking a vehicle in a roadway.


  1. Be alert.
  2. Remain standing at all times, and face oncoming traffic.
  3. Park vehicles off the road and away from the flagger station.
  4. Never turn or look away from oncoming traffic.
  5. Never stand in the path of moving traffic.
  6. Never stand near or between parked vehicles on the roadside.
  7. Nothing should be near the flagger—no devices such as music players or smart phones. Roadsides are inherently dangerous.
  8. No person should be near the flagger. Other people may distract the flagger, or, worse, may be hit along with a flagger by an errant vehicle.
  9. Under no circumstances should a flagger stop flagging until the blocked lanes(s) are clear. This is true regardless of whether the P/EVO is controlling traffic behind the load or controlling oncoming lane(s) of traffic.
  10. Never lean on vehicles; be polite but brief. Never argue with a motorist.


If a driver ignores the flagger's instructions, do not stop flagging. First, warn people in the control zone/activity area of the presence of the errant vehicle. Get a description of the vehicle, including the tag number if possible. Finally, report the motorist to authorities.

Flaggers should have frequent breaks (no more than two hours of flagging, or as required by the States). The hotter, colder, windier, or wetter the conditions, the more frequently flaggers should have breaks.

It is important for P/EVOs to be aware of traffic conditions at nearby intersections, especially in high-volume intersections and/or during peak traffic times. It is important that P/EVOs avoid causing potentially dangerous situations, including traffic backups at intersections or on exit and entry ramps, for example. Traffic tie-ups create an environment that is ripe for collisions. Note that when an intersection exists within the activity area, an additional flagger may be needed to control traffic entering from that intersection.

Remember, emergency vehicles have priority. When emergency vehicles approach, flaggers should stop all traffic under their control until the emergency vehicle has cleared the area.


As a reminder, States differ in the authority extended to P/EVOs to control traffic. Many States allow it, but others do not. As mentioned, if P/EVOs are not authorized to control traffic in a given jurisdiction, the responsibility for doing this is typically delegated to law enforcement officials—and these officials are in charge of the load movement while they are engaged in the traffic control process.

2 The FHWA has incorporated by reference the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD), pursuant to 23 CFR 655.601(d)(2). [ Return to note 2. ]

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