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Incoming Interpretation Letter 6(09)-5 (I) - Use of Pilot Car with Temporary Traffic Control Signals

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June 24, 2010

Mr. Hari Kalla
MUTCD Team Leader
Federal Highway Administration, Office of Operations
1200 New Jersey Ave, SE
Room E84-316
Washington, District of Columbia 20590

Subject: Interpretation MUTCD Temporary Traffic Control for Figure 6H-12 (Typical Application 12)

Dear Mr. Kalla

We are requesting an interpretation that would permit a Pilot Car to be used as an Option in Typical Application 12, Lane Closure on a Two-Lane Road Using Traffic Control Signals to expand the safety of the motoring public.

The Portable Traffic System, PTS 2000, has the ability to allow the PILOT CAR driver to control the actuation of the traffic signal and the amount of GREEN time allocated to a movement to effectively and safely move traffic through a WORK ZONE no matter what the distance. The method is called a PILOT CAR MODULE.

The duration of the green interval is controlled by the operator of the Pilot Car and is predicted on the amount of queued traffic. The yellow clearance interval is established in accordance with standards provided in Section 4D-26. Travel speed through the work zone, and clearance time, is controlled by the speed of the Pilot Car, including any delays that might be encountered. When the Pilot Car reaches the end of the one-lane section and the traffic waiting in the opposite direction, it pulls off to the side of the road to allow the traffic that was just led through the Work Zone to pass. The Pilot Car then turns around to get in front of the opposing traffic for the return trip, setting the duration of upcoming green interval based again on the amount of queued traffic. All required timing input is done with the Pilot Car Module from within the Pilot Car. The method has been used in many Western States for more than ten years with no incidents and great success

Portable Traffic Signals are a more positive traffic control as they can be seen at a greater distance causing the motorist to be more responsive and remove the FLAGGER from harms way.

As noted in the Notes for Figure 6H-12 Support: paragraph #10, Temporary Signals are preferable to flaggers…, with this in mind and the success of Portable Traffic Signals proven over the years as a positive control, we request that Pilot Car operations be included as an Option in Typical Application 12.

Should additional information be required please advise.


Robert J. Burns

John Thomas, Inc. | 1560 Lovett Drive | Dixon, Illinois 61021 | Tel: 888-447-7263 | Fax: 888-335-3948 |

Figure 6H-12. Lane Closure on a Two-Lane Road Using Traffic Control Signals (TA-12)

Image of Figure 6H-12. Lane Closure on a Two-Lane Road Using Traffic Control Signals (TA-12)

Notes for Figure 6H-12—Typical Application 12
Lane Closure on a Two-Lane Road Using Traffic Control Signals


  1. Temporary traffic control signals shall be installed and operated in accordance with the provisions of Part 4. Temporary traffic control signals shall meet the physical display and operational requirements of conventional traffic control signals.
  2. Temporary traffic control signal timing shall be established by authorized officials. Durations of red clearance intervals shall be adequate to clear the one-lane section of conflicting vehicles.
  3. When the temporary traffic control signal is changed to the flashing mode, either manually or automatically, red signal indications shall be flashed to both approaches.
  4. Stop lines shall be installed with temporary traffic control signals for intermediate and long-term closures. Existing conflicting pavement markings and raised pavement marker reflectors between the activity area and the stop line shall be removed. After the temporary traffic control signal is removed, the stop lines and other temporary pavement markings shall be removed and the permanent pavement markings restored.
  5. Safeguards shall be incorporated to avoid the possibility of conflicting signal indications at each end of the TTC zone.


  1. Where no-passing lines are not already in place, they should be added.
  2. Adjustments in the location of the advance warning signs should be made as needed to accommodate the horizontal or vertical alignment of the roadway, recognizing that the distances shown for sign spacings are minimums. Adjustments in the height of the signal heads should be made as needed to conform to the vertical alignment.


  1. Flashing warning lights shown on the ROAD WORK AHEAD and the ONE LANE ROAD AHEAD signs may be used.
  2. Removable pavement markings may be used.


  1. Temporary traffic control signals are preferable to flaggers for long-term projects and other activities that would require flagging at night.
  2. The maximum length of activity area for one-way operation under temporary traffic control signal control is determined by the capacity required to handle the peak demand.

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