Flashing Arrow Panels

Arrow panels are traffic control devices used for additional advance warning and where a lane is closed, and traffic must merge with traffic in an adjacent lane. They are generally used for lane closure, and slow-moving maintenance activities. Arrow Panels are used in conjunction with advance warning signs. Required advance-warning signs shall not be omitted based on the presence of an Arrow Panel(s)

  • The arrow display should NEVER be used on two-lane, two-way roads. Arrow displays should only be used where traffic can be moved to another lane without danger of meeting on-coming traffic…multi-lane, single direction roadways.
  • The four-corner flash mode may be used to provide additional advance warning where an arrow display is not appropriate.


  • Locate arrow panels to maximize the distance between the arrow panel and the point where drivers first must see and understand the arrow. Provide at least ½ mile legibility (more if possible) for highways with speed limits of 45 mph or greater. Trailer mounted arrow panels should be 4 feet high by 8 feet wide, mounted at a height of 7 feet. Provide at least 1500-foot legibility if used where speed limits are below 45 mph.

For stationary lane closures, place the arrow panel on the shoulder inside the taper near the beginning of the taper. Avoid placing it near ramps, median crossovers, and intersections where it may confuse drivers. Use only one arrow panel for each stationary lane closure. Too many arrow panels can encourage drivers to change lanes unnecessarily.

For mobile maintenance activities where a lane is closed, an arrow panel must be placed in the closed lane at the rear of the activity. If possible, use two arrow panels for mobile/moving work zones; one on the first shadow vehicle in the closed lane, and the second on a shadow vehicle, pick-up truck or trailer on the shoulder upstream of the first one. The arrow panel should be placed on a vehicle separate from a work vehicle and positioned between the last work vehicle and approaching traffic.

In areas with restricted sight distance, it may be necessary for the arrow panel vehicle to lag behind or stop and wait behind the activity to maintain optimal visibility to approaching traffic.  As sight distance improves behind the activity, the arrow panel vehicle should close the gap.  However, the distance between the arrow panel vehicle and the work activity should be kept short enough to discourage drivers from re-entering the lane. 

Figure and Table 6: Advance Warning Arrow